version: 3.4.0

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>

.travis.yml

@@ -6,8 +6,7 @@ sudo: required
 services: docker
 
 go:
-- 1.12.7
-- tip
+- 1.12.9
 
 notifications:
   on_success: never
@@ -23,45 +22,14 @@ env:
   - TARGET=linux-amd64-unit
   - TARGET=all-build
   - TARGET=linux-amd64-grpcproxy
-  - TARGET=linux-amd64-coverage
-  - TARGET=linux-amd64-fmt-unit-go-tip
   - TARGET=linux-386-unit
 
 matrix:
   fast_finish: true
   allow_failures:
-  - go: 1.12.7
-    env: TARGET=linux-amd64-integration-4-cpu
-  - go: 1.12.7
+  - go: 1.12.9
     env: TARGET=linux-amd64-grpcproxy
-  - go: 1.12.7
-    env: TARGET=linux-amd64-coverage
-  - go: tip
-    env: TARGET=linux-amd64-fmt-unit-go-tip
-  - go: 1.12.7
-    env: TARGET=linux-386-unit
-  exclude:
-  - go: tip
-    env: TARGET=linux-amd64-fmt
-  - go: tip
-    env: TARGET=linux-amd64-integration-1-cpu
-  - go: tip
-    env: TARGET=linux-amd64-integration-2-cpu
-  - go: tip
-    env: TARGET=linux-amd64-integration-4-cpu
-  - go: tip
-    env: TARGET=linux-amd64-functional
-  - go: tip
-    env: TARGET=linux-amd64-unit
-  - go: tip
-    env: TARGET=all-build
-  - go: tip
-    env: TARGET=linux-amd64-grpcproxy
-  - go: tip
-    env: TARGET=linux-amd64-coverage
-  - go: 1.12.7
-    env: TARGET=linux-amd64-fmt-unit-go-tip
-  - go: tip
+  - go: 1.12.9
     env: TARGET=linux-386-unit
 
 before_install:
@@ -118,12 +86,6 @@ script:
       linux-amd64-grpcproxy)
         sudo HOST_TMP_DIR=/tmp TEST_OPTS="PASSES='build grpcproxy'" make docker-test
         ;;
-      linux-amd64-coverage)
-        sudo HOST_TMP_DIR=/tmp make docker-test-coverage
-        ;;
-      linux-amd64-fmt-unit-go-tip)
-        GOARCH=amd64 PASSES='fmt unit' ./test
-        ;;
       linux-386-unit)
         docker run --rm \
           --volume=`pwd`:/go/src/go.etcd.io/etcd gcr.io/etcd-development/etcd-test:go${TRAVIS_GO_VERSION} \

CHANGELOG-2.3.md

@@ -1,16 +0,0 @@
-
-
-<hr>
-
-
-## [v2.3.8](https://github.com/etcd-io/etcd/releases/tag/v2.3.8) (2017-02-17)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v2.3.7...v2.3.8).
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-

CHANGELOG-3.0.md

@@ -1,291 +0,0 @@
-
-
-<hr>
-
-
-## [v3.0.16](https://github.com/etcd-io/etcd/releases/tag/v3.0.16) (2016-11-13)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.15...v3.0.16) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.4*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.15](https://github.com/etcd-io/etcd/releases/tag/v3.0.15) (2016-11-11)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.14...v3.0.15) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Fixed
-
-- Fix cancel watch request with wrong range end.
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.14](https://github.com/etcd-io/etcd/releases/tag/v3.0.14) (2016-11-04)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.13...v3.0.14) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Added
-
-- v3 `etcdctl migrate` command now supports `--no-ttl` flag to discard keys on transform.
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.13](https://github.com/etcd-io/etcd/releases/tag/v3.0.13) (2016-10-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.12...v3.0.13) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.12](https://github.com/etcd-io/etcd/releases/tag/v3.0.12) (2016-10-07)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.11...v3.0.12) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.11](https://github.com/etcd-io/etcd/releases/tag/v3.0.11) (2016-10-07)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.10...v3.0.11) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Added
-
-- Server returns previous key-value (optional)
-  - `clientv3.WithPrevKV` option
-  - v3 etcdctl `put,watch,del --prev-kv` flag
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.10](https://github.com/etcd-io/etcd/releases/tag/v3.0.10) (2016-09-23)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.9...v3.0.10) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.9](https://github.com/etcd-io/etcd/releases/tag/v3.0.9) (2016-09-15)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.8...v3.0.9) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Added
-
-- Warn on domain names on listen URLs (v3.2 will reject domain names).
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.8](https://github.com/etcd-io/etcd/releases/tag/v3.0.8) (2016-09-09)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.7...v3.0.8) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Other
-
-- Allow only IP addresses in listen URLs (domain names are rejected).
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.7](https://github.com/etcd-io/etcd/releases/tag/v3.0.7) (2016-08-31)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.6...v3.0.7) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Other
-
-- SRV records only allow A records (RFC 2052).
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.6](https://github.com/etcd-io/etcd/releases/tag/v3.0.6) (2016-08-19)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.5...v3.0.6) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.5](https://github.com/etcd-io/etcd/releases/tag/v3.0.5) (2016-08-19)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.4...v3.0.5) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Other
-
-- SRV records (e.g., infra1.example.com) must match the discovery domain (i.e., example.com) if no custom certificate authority is given.
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.4](https://github.com/etcd-io/etcd/releases/tag/v3.0.4) (2016-07-27)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.3...v3.0.4) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Added
-
-- v2 `etcdctl ls` command now supports `--output=json`.
-- Add /var/lib/etcd directory to etcd official Docker image.
-
-### Other
-
-- v2 auth can now use common name from TLS certificate when `--client-cert-auth` is enabled.
-
-### Go
-
-- Compile with [*Go 1.6.3*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.3](https://github.com/etcd-io/etcd/releases/tag/v3.0.3) (2016-07-15)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.2...v3.0.3) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Other
-
-- Revert Dockerfile to use `CMD`, instead of `ENTRYPOINT`, to support `etcdctl` run.
-  - Docker commands for v3.0.2 won't work without specifying executable binary paths.
-- v3 etcdctl default endpoints are now `127.0.0.1:2379`.
-
-### Go
-
-- Compile with [*Go 1.6.2*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.2](https://github.com/etcd-io/etcd/releases/tag/v3.0.2) (2016-07-08)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.1...v3.0.2) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Other
-
-- Dockerfile uses `ENTRYPOINT`, instead of `CMD`, to run etcd without binary path specified.
-
-### Go
-
-- Compile with [*Go 1.6.2*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.1](https://github.com/etcd-io/etcd/releases/tag/v3.0.1) (2016-07-01)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.0...v3.0.1) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.2*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-
-
-## [v3.0.0](https://github.com/etcd-io/etcd/releases/tag/v3.0.0) (2016-06-30)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v2.3.0...v3.0.0) and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_0.md).**
-
-### Go
-
-- Compile with [*Go 1.6.2*](https://golang.org/doc/devel/release.html#go1.6).
-
-
-<hr>
-

CHANGELOG-3.1.md

@@ -1,574 +0,0 @@
-
-
-Previous change logs can be found at [CHANGELOG-3.0](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.0.md).
-
-
-The minimum recommended etcd versions to run in **production** are 3.1.11+, 3.2.26+, and 3.3.11+.
-
-
-<hr>
-
-## [v3.1.21](https://github.com/etcd-io/etcd/releases/tag/v3.1.21) (2019-TBD)
-
-### etcdctl
-
-- [Strip out insecure endpoints from DNS SRV records when using discovery](https://github.com/etcd-io/etcd/pull/10443) with etcdctl v2
-- Add [`etcdctl endpoint health --write-out` support](https://github.com/etcd-io/etcd/pull/9540).
-  - Previously, [`etcdctl endpoint health --write-out json` did not work](https://github.com/etcd-io/etcd/issues/9532).
-  - The command output is changed. Previously, if endpoint is unreachable, the command output is
-  "\<endpoint\> is unhealthy: failed to connect: \<error message\>". This change unified the error message, all error types
-  now have the same output "\<endpoint\> is unhealthy: failed to commit proposal: \<error message\>".
-
-### Metrics, Monitoring
-
-- Fix bug where [db_compaction_total_duration_milliseconds metric incorrectly measured duration as 0](https://github.com/etcd-io/etcd/pull/10646).
-
-<hr>
-
-## [v3.1.20](https://github.com/etcd-io/etcd/releases/tag/v3.1.20) (2018-10-10)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.19...v3.1.20) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Improved
-
-- Improve ["became inactive" warning log](https://github.com/etcd-io/etcd/pull/10024), which indicates message send to a peer failed.
-- Improve [read index wait timeout warning log](https://github.com/etcd-io/etcd/pull/10026), which indicates that local node might have slow network.
-- Add [gRPC interceptor for debugging logs](https://github.com/etcd-io/etcd/pull/9990); enable `etcd --debug` flag to see per-request debug information.
-- Add [consistency check in snapshot status](https://github.com/etcd-io/etcd/pull/10109). If consistency check on snapshot file fails, `snapshot status` returns `"snapshot file integrity check failed..."` error.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.1.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Improve [`etcd_network_peer_round_trip_time_seconds`](https://github.com/etcd-io/etcd/pull/10155) Prometheus metric to track leader heartbeats.
-  - Previously, it only samples the TCP connection for snapshot messages.
-- Display all registered [gRPC metrics at start](https://github.com/etcd-io/etcd/pull/10034).
-- Add [`etcd_snap_db_fsync_duration_seconds_count`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_snap_db_save_total_duration_seconds_bucket`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_server_id`](https://github.com/etcd-io/etcd/pull/9998) Prometheus metric.
-- Add [`etcd_server_health_success`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_health_failures`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_read_indexes_failed_total`](https://github.com/etcd-io/etcd/pull/10094) Prometheus metric.
-
-### client v3
-
-- Fix logic on [release lock key if cancelled](https://github.com/etcd-io/etcd/pull/10153) in `clientv3/concurrency` package.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.19](https://github.com/etcd-io/etcd/releases/tag/v3.1.19) (2018-07-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.18...v3.1.19) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Improved
-
-- Improve [Raft Read Index timeout warning messages](https://github.com/etcd-io/etcd/pull/9897).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.1.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_go_version`](https://github.com/etcd-io/etcd/pull/9957) Prometheus metric.
-- Add [`etcd_server_slow_read_indexes_total`](https://github.com/etcd-io/etcd/pull/9897) Prometheus metric.
-- Add [`etcd_server_quota_backend_bytes`](https://github.com/etcd-io/etcd/pull/9820) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-- Add [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819) Prometheus metric.
-  - In addition to [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819).
-- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/etcd-io/etcd/pull/9256) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-
-### client v3
-
-- Fix [lease keepalive interval updates when response queue is full](https://github.com/etcd-io/etcd/pull/9952).
-  - If `<-chan *clientv3LeaseKeepAliveResponse` from `clientv3.Lease.KeepAlive` was never consumed or channel is full, client was [sending keepalive request every 500ms](https://github.com/etcd-io/etcd/issues/9911) instead of expected rate of every "TTL / 3" duration.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.18](https://github.com/etcd-io/etcd/releases/tag/v3.1.18) (2018-06-15)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.17...v3.1.18) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.1.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_version`](https://github.com/etcd-io/etcd/pull/8960) Prometheus metric.
-  - To replace [Kubernetes `etcd-version-monitor`](https://github.com/etcd-io/etcd/issues/8948).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.17](https://github.com/etcd-io/etcd/releases/tag/v3.1.17) (2018-06-06)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.16...v3.1.17) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Fix [v3 snapshot recovery](https://github.com/etcd-io/etcd/issues/7628).
-  - A follower receives a leader snapshot to be persisted as a `[SNAPSHOT-INDEX].snap.db` file on disk.
-  - Now, server [ensures that the incoming snapshot be persisted on disk before loading it](https://github.com/etcd-io/etcd/pull/7876).
-  - Otherwise, index mismatch happens and triggers server-side panic (e.g. newer WAL entry with outdated snapshot index).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.16](https://github.com/etcd-io/etcd/releases/tag/v3.1.16) (2018-05-31)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.15...v3.1.16) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Fix [`mvcc` server panic from restore operation](https://github.com/etcd-io/etcd/pull/9775).
-  - Let's assume that a watcher had been requested with a future revision X and sent to node A that became network-partitioned thereafter. Meanwhile, cluster makes progress. Then when the partition gets removed, the leader sends a snapshot to node A. Previously if the snapshot's latest revision is still lower than the watch revision X,  **etcd server panicked** during snapshot restore operation.
-  - Now, this server-side panic has been fixed.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.15](https://github.com/etcd-io/etcd/releases/tag/v3.1.15) (2018-05-09)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.14...v3.1.15) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Purge old [`*.snap.db` snapshot files](https://github.com/etcd-io/etcd/pull/7967).
-  - Previously, etcd did not respect `--max-snapshots` flag to purge old `*.snap.db` files.
-  - Now, etcd purges old `*.snap.db` files to keep maximum `--max-snapshots` number of files on disk.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.14](https://github.com/etcd-io/etcd/releases/tag/v3.1.14) (2018-04-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.13...v3.1.14) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.1.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_is_leader`](https://github.com/etcd-io/etcd/pull/9587) Prometheus metric.
-
-### etcd server
-
-- Add [`--initial-election-tick-advance`](https://github.com/etcd-io/etcd/pull/9591) flag to configure initial election tick fast-forward.
-  - By default, `--initial-election-tick-advance=true`, then local member fast-forwards election ticks to speed up "initial" leader election trigger.
-  - This benefits the case of larger election ticks. For instance, cross datacenter deployment may require longer election timeout of 10-second. If true, local node does not need wait up to 10-second. Instead, forwards its election ticks to 8-second, and have only 2-second left before leader election.
-  - Major assumptions are that: cluster has no active leader thus advancing ticks enables faster leader election. Or cluster already has an established leader, and rejoining follower is likely to receive heartbeats from the leader after tick advance and before election timeout.
-  - However, when network from leader to rejoining follower is congested, and the follower does not receive leader heartbeat within left election ticks, disruptive election has to happen thus affecting cluster availabilities.
-  - Now, this can be disabled by setting `--initial-election-tick-advance=false`.
-  - Disabling this would slow down initial bootstrap process for cross datacenter deployments. Make tradeoffs by configuring `--initial-election-tick-advance` at the cost of slow initial bootstrap.
-  - If single-node, it advances ticks regardless.
-  - Address [disruptive rejoining follower node](https://github.com/etcd-io/etcd/issues/9333).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.13](https://github.com/etcd-io/etcd/releases/tag/v3.1.13) (2018-03-29)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.12...v3.1.13) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Improved
-
-- Adjust [election timeout on server restart](https://github.com/etcd-io/etcd/pull/9415) to reduce [disruptive rejoining servers](https://github.com/etcd-io/etcd/issues/9333).
-  - Previously, etcd fast-forwards election ticks on server start, with only one tick left for leader election. This is to speed up start phase, without having to wait until all election ticks elapse. Advancing election ticks is useful for cross datacenter deployments with larger election timeouts. However, it was affecting cluster availability if the last tick elapses before leader contacts the restarted node.
-  - Now, when etcd restarts, it adjusts election ticks with more than one tick left, thus more time for leader to prevent disruptive restart.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.1.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add missing [`etcd_network_peer_sent_failures_total` count](https://github.com/etcd-io/etcd/pull/9437).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.12](https://github.com/etcd-io/etcd/releases/tag/v3.1.12) (2018-03-08)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.11...v3.1.12) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Fix [`mvcc` "unsynced" watcher restore operation](https://github.com/etcd-io/etcd/pull/9297).
-  - "unsynced" watcher is watcher that needs to be in sync with events that have happened.
-  - That is, "unsynced" watcher is the slow watcher that was requested on old revision.
-  - "unsynced" watcher restore operation was not correctly populating its underlying watcher group.
-  - Which possibly causes [missing events from "unsynced" watchers](https://github.com/etcd-io/etcd/issues/9086).
-  - A node gets network partitioned with a watcher on a future revision, and falls behind receiving a leader snapshot after partition gets removed. When applying this snapshot, etcd watch storage moves current synced watchers to unsynced since sync watchers might have become stale during network partition. And reset synced watcher group to restart watcher routines. Previously, there was a bug when moving from synced watcher group to unsynced, thus client would miss events when the watcher was requested to the network-partitioned node.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.11](https://github.com/etcd-io/etcd/releases/tag/v3.1.11) (2017-11-28)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.10...v3.1.11) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- [#8411](https://github.com/etcd-io/etcd/issues/8411),[#8806](https://github.com/etcd-io/etcd/pull/8806) backport "mvcc: sending events after restore"
-- [#8009](https://github.com/etcd-io/etcd/issues/8009),[#8902](https://github.com/etcd-io/etcd/pull/8902) backport coreos/bbolt v1.3.1-coreos.5
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.1.10](https://github.com/etcd-io/etcd/releases/tag/v3.1.10) (2017-07-14)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.9...v3.1.10) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Added
-
-- Tag docker images with minor versions.
-  - e.g. `docker pull quay.io/coreos/etcd:v3.1` to fetch latest v3.1 versions.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-  - Fix panic on `net/http.CloseNotify`
-
-
-<hr>
-
-
-## [v3.1.9](https://github.com/etcd-io/etcd/releases/tag/v3.1.9) (2017-06-09)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.8...v3.1.9) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Allow v2 snapshot over 512MB.
-
-### Go
-
-- Compile with [*Go 1.7.6*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.8](https://github.com/etcd-io/etcd/releases/tag/v3.1.8) (2017-05-19)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.7...v3.1.8) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.7](https://github.com/etcd-io/etcd/releases/tag/v3.1.7) (2017-04-28)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.6...v3.1.7) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.6](https://github.com/etcd-io/etcd/releases/tag/v3.1.6) (2017-04-19)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.5...v3.1.6) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Fill in Auth API response header.
-- Remove auth check in Status API.
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.5](https://github.com/etcd-io/etcd/releases/tag/v3.1.5) (2017-03-27)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.4...v3.1.5) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd server
-
-- Fix raft memory leak issue.
-- Fix Windows file path issues.
-
-### Other
-
-- Add `/etc/nsswitch.conf` file to alpine-based Docker image.
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.4](https://github.com/etcd-io/etcd/releases/tag/v3.1.4) (2017-03-22)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.3...v3.1.4) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.3](https://github.com/etcd-io/etcd/releases/tag/v3.1.3) (2017-03-10)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.2...v3.1.3) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd gateway
-
-- Fix `etcd gateway` schema handling in DNS discovery.
-- Fix sd_notify behaviors in `gateway`, `grpc-proxy`.
-
-### gRPC Proxy
-
-- Fix sd_notify behaviors in `gateway`, `grpc-proxy`.
-
-### Other
-
-- Use machine default host when advertise URLs are default values(`localhost:2379,2380`) AND if listen URL is `0.0.0.0`.
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.2](https://github.com/etcd-io/etcd/releases/tag/v3.1.2) (2017-02-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.1...v3.1.2) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### etcd gateway
-
-- Fix `etcd gateway` with multiple endpoints.
-
-### Other
-
-- Use IPv4 default host, by default (when IPv4 and IPv6 are available).
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.1](https://github.com/etcd-io/etcd/releases/tag/v3.1.1) (2017-02-17)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.0...v3.1.1) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Go
-
-- Compile with [*Go 1.7.5*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-
-
-## [v3.1.0](https://github.com/etcd-io/etcd/releases/tag/v3.1.0) (2017-01-20)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.0.0...v3.1.0) and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.1 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_1.md).**
-
-### Improved
-
-- Faster linearizable reads (implements Raft [read-index](https://github.com/etcd-io/etcd/pull/6212)).
-- v3 authentication API is now stable.
-
-### Breaking Changes
-
-- Deprecated following gRPC metrics in favor of [go-grpc-prometheus](https://github.com/grpc-ecosystem/go-grpc-prometheus).
-  - `etcd_grpc_requests_total`
-  - `etcd_grpc_requests_failed_total`
-  - `etcd_grpc_active_streams`
-  - `etcd_grpc_unary_requests_duration_seconds`
-
-### Dependency
-
-- Upgrade [`github.com/ugorji/go/codec`](https://github.com/ugorji/go) to [**`ugorji/go@9c7f9b7`**](https://github.com/ugorji/go/commit/9c7f9b7a2bc3a520f7c7b30b34b7f85f47fe27b6), and [regenerate v2 `client`](https://github.com/etcd-io/etcd/pull/6945).
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- SRV records (e.g., infra1.example.com) must match the discovery domain (i.e., example.com) if no custom certificate authority is given.
-  - `TLSConfig.ServerName` is ignored with user-provided certificates for backwards compatibility; to be deprecated.
-  - For example, `etcd --discovery-srv=example.com` will only authenticate peers/clients when the provided certs have root domain `example.com` as an entry in Subject Alternative Name (SAN) field.
-
-### etcd server
-
-- Automatic leadership transfer when leader steps down.
-- etcd flags
-  - `--strict-reconfig-check` flag is set by default.
-  - Add `--log-output` flag.
-  - Add `--metrics` flag.
-- etcd uses default route IP if advertise URL is not given.
-- Cluster rejects removing members if quorum will be lost.
-- Discovery now has upper limit for waiting on retries.
-- Warn on binding listeners through domain names; to be deprecated.
-- v3.0 and v3.1 with `--auto-compaction-retention=10` run periodic compaction on v3 key-value store for every 10-hour.
-  - Compactor only supports periodic compaction.
-  - Compactor records latest revisions every 5-minute, until it reaches the first compaction period (e.g. 10-hour).
-  - In order to retain key-value history of last compaction period, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute.
-  - When `--auto-compaction-retention=10`, compactor uses revision 100 for compact revision where revision 100 is the latest revision fetched from 10 hours ago.
-  - If compaction succeeds or requested revision has already been compacted, it resets period timer and starts over with new historical revision records (e.g. restart revision collect and compact for the next 10-hour period).
-  - If compaction fails, it retries in 5 minutes.
-
-### client v3
-
-- Add `SetEndpoints` method; update endpoints at runtime.
-- Add `Sync` method; auto-update endpoints at runtime.
-- Add `Lease TimeToLive` API; fetch lease information.
-- replace Config.Logger field with global logger.
-- Get API responses are sorted in ascending order by default.
-
-### etcdctl v3
-
-- Add `lease timetolive` command.
-- Add `--print-value-only` flag to get command.
-- Add `--dest-prefix` flag to make-mirror command.
-- `get` command responses are sorted in ascending order by default.
-
-### gRPC Proxy
-
-- Experimental gRPC proxy feature.
-
-### Other
-
-- `recipes` now conform to sessions defined in `clientv3/concurrency`.
-- ACI has symlinks to `/usr/local/bin/etcd*`.
-
-### Go
-
-- Compile with [*Go 1.7.4*](https://golang.org/doc/devel/release.html#go1.7).
-
-
-<hr>
-

CHANGELOG-3.2.md

@@ -1,884 +0,0 @@
-
-
-Previous change logs can be found at [CHANGELOG-3.1](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.1.md).
-
-
-The minimum recommended etcd versions to run in **production** are 3.1.11+, 3.2.26+, and 3.3.11+.
-
-
-<hr>
-
-
-## [v3.2.27](https://github.com/etcd-io/etcd/releases/tag/v3.2.27) (2019-TBD)
-
-### etcdctl
-
-- [Strip out insecure endpoints from DNS SRV records when using discovery](https://github.com/etcd-io/etcd/pull/10443) with etcdctl v2
-- Add [`etcdctl endpoint health --write-out` support](https://github.com/etcd-io/etcd/pull/9540).
-  - Previously, [`etcdctl endpoint health --write-out json` did not work](https://github.com/etcd-io/etcd/issues/9532).
-  - The command output is changed. Previously, if endpoint is unreachable, the command output is
-  "\<endpoint\> is unhealthy: failed to connect: \<error message\>". This change unified the error message, all error types
-  now have the same output "\<endpoint\> is unhealthy: failed to commit proposal: \<error message\>".
-
-### Metrics, Monitoring
-
-- Fix bug where [db_compaction_total_duration_milliseconds metric incorrectly measured duration as 0](https://github.com/etcd-io/etcd/pull/10646).
-
-<hr>
-
-
-## [v3.2.26](https://github.com/etcd-io/etcd/releases/tag/v3.2.26) (2019-01-11)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.25...v3.2.26) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### gRPC Proxy
-
-- Fix [memory leak in cache layer](https://github.com/etcd-io/etcd/pull/10327).
-
-### Security, Authentication
-
-- Disable [CommonName authentication for gRPC-gateway](https://github.com/etcd-io/etcd/pull/10366) gRPC-gateway proxy requests to etcd server use the etcd client server TLS certificate. If that certificate contains CommonName we do not want to use that for authentication as it could lead to permission escalation.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.25](https://github.com/etcd-io/etcd/releases/tag/v3.2.25) (2018-10-10)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.24...v3.2.25) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Improve ["became inactive" warning log](https://github.com/etcd-io/etcd/pull/10024), which indicates message send to a peer failed.
-- Improve [read index wait timeout warning log](https://github.com/etcd-io/etcd/pull/10026), which indicates that local node might have slow network.
-- Add [gRPC interceptor for debugging logs](https://github.com/etcd-io/etcd/pull/9990); enable `etcd --debug` flag to see per-request debug information.
-- Add [consistency check in snapshot status](https://github.com/etcd-io/etcd/pull/10109). If consistency check on snapshot file fails, `snapshot status` returns `"snapshot file integrity check failed..."` error.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.17/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Improve [`etcd_network_peer_round_trip_time_seconds`](https://github.com/etcd-io/etcd/pull/10155) Prometheus metric to track leader heartbeats.
-  - Previously, it only samples the TCP connection for snapshot messages.
-- Display all registered [gRPC metrics at start](https://github.com/etcd-io/etcd/pull/10032).
-- Add [`etcd_snap_db_fsync_duration_seconds_count`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_snap_db_save_total_duration_seconds_bucket`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_server_id`](https://github.com/etcd-io/etcd/pull/9998) Prometheus metric.
-- Add [`etcd_server_health_success`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_health_failures`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_read_indexes_failed_total`](https://github.com/etcd-io/etcd/pull/10094) Prometheus metric.
-
-### client v3
-
-- Fix logic on [release lock key if cancelled](https://github.com/etcd-io/etcd/pull/10153) in `clientv3/concurrency` package.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.24](https://github.com/etcd-io/etcd/releases/tag/v3.2.24) (2018-07-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.23...v3.2.24) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Improve [Raft Read Index timeout warning messages](https://github.com/etcd-io/etcd/pull/9897).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_go_version`](https://github.com/etcd-io/etcd/pull/9957) Prometheus metric.
-- Add [`etcd_server_heartbeat_send_failures_total`](https://github.com/etcd-io/etcd/pull/9942) Prometheus metric.
-- Add [`etcd_server_slow_apply_total`](https://github.com/etcd-io/etcd/pull/9942) Prometheus metric.
-- Add [`etcd_disk_backend_defrag_duration_seconds`](https://github.com/etcd-io/etcd/pull/9942) Prometheus metric.
-- Add [`etcd_mvcc_hash_duration_seconds`](https://github.com/etcd-io/etcd/pull/9942) Prometheus metric.
-- Add [`etcd_server_slow_read_indexes_total`](https://github.com/etcd-io/etcd/pull/9897) Prometheus metric.
-- Add [`etcd_server_quota_backend_bytes`](https://github.com/etcd-io/etcd/pull/9820) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-- Add [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819) Prometheus metric.
-  - In addition to [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819).
-- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/etcd-io/etcd/pull/9256) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_server_quota_backend_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-
-### gRPC Proxy
-
-- Add [flags for specifying TLS for connecting to proxy](https://github.com/etcd-io/etcd/pull/9894):
-  - Add `grpc-proxy start --cert-file`, `grpc-proxy start --key-file` and `grpc-proxy start --trusted-ca-file` flags.
-- Add [`grpc-proxy start --metrics-addr` flag for specifying a separate metrics listen address](https://github.com/etcd-io/etcd/pull/9894).
-
-### client v3
-
-- Fix [lease keepalive interval updates when response queue is full](https://github.com/etcd-io/etcd/pull/9952).
-  - If `<-chan *clientv3LeaseKeepAliveResponse` from `clientv3.Lease.KeepAlive` was never consumed or channel is full, client was [sending keepalive request every 500ms](https://github.com/etcd-io/etcd/issues/9911) instead of expected rate of every "TTL / 3" duration.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.23](https://github.com/etcd-io/etcd/releases/tag/v3.2.23) (2018-06-15)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.22...v3.2.23) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Improve [slow request apply warning log](https://github.com/etcd-io/etcd/pull/9288).
-  - e.g. `read-only range request "key:\"/a\" range_end:\"/b\" " with result "range_response_count:3 size:96" took too long (97.966µs) to execute`.
-  - Redact [request value field](https://github.com/etcd-io/etcd/pull/9822).
-  - Provide [response size](https://github.com/etcd-io/etcd/pull/9826).
-- Add [backoff on watch retries on transient errors](https://github.com/etcd-io/etcd/pull/9840).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_version`](https://github.com/etcd-io/etcd/pull/8960) Prometheus metric.
-  - To replace [Kubernetes `etcd-version-monitor`](https://github.com/etcd-io/etcd/issues/8948).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.22](https://github.com/etcd-io/etcd/releases/tag/v3.2.22) (2018-06-06)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.21...v3.2.22) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Security, Authentication
-
-- Support TLS cipher suite whitelisting.
-  - To block [weak cipher suites](https://github.com/etcd-io/etcd/issues/8320).
-  - TLS handshake fails when client hello is requested with invalid cipher suites.
-  - Add [`etcd --cipher-suites`](https://github.com/etcd-io/etcd/pull/9801) flag.
-  - If empty, Go auto-populates the list.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.21](https://github.com/etcd-io/etcd/releases/tag/v3.2.21) (2018-05-31)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.20...v3.2.21) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Fix [auth storage panic when simple token provider is disabled](https://github.com/etcd-io/etcd/pull/8695).
-- Fix [`mvcc` server panic from restore operation](https://github.com/etcd-io/etcd/pull/9775).
-  - Let's assume that a watcher had been requested with a future revision X and sent to node A that became network-partitioned thereafter. Meanwhile, cluster makes progress. Then when the partition gets removed, the leader sends a snapshot to node A. Previously if the snapshot's latest revision is still lower than the watch revision X,  **etcd server panicked** during snapshot restore operation.
-  - Now, this server-side panic has been fixed.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.20](https://github.com/etcd-io/etcd/releases/tag/v3.2.20) (2018-05-09)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.19...v3.2.20) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Purge old [`*.snap.db` snapshot files](https://github.com/etcd-io/etcd/pull/7967).
-  - Previously, etcd did not respect `--max-snapshots` flag to purge old `*.snap.db` files.
-  - Now, etcd purges old `*.snap.db` files to keep maximum `--max-snapshots` number of files on disk.
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.19](https://github.com/etcd-io/etcd/releases/tag/v3.2.19) (2018-04-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.18...v3.2.19) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Fix [`etcd_debugging_server_lease_expired_total`](https://github.com/etcd-io/etcd/pull/9557) Prometheus metric.
-- Fix [race conditions in v2 server stat collecting](https://github.com/etcd-io/etcd/pull/9562).
-- Add [`etcd_server_is_leader`](https://github.com/etcd-io/etcd/pull/9587) Prometheus metric.
-
-### Security, Authentication
-
-- Fix [TLS reload](https://github.com/etcd-io/etcd/pull/9570) when [certificate SAN field only includes IP addresses but no domain names](https://github.com/etcd-io/etcd/issues/9541).
-  - In Go, server calls `(*tls.Config).GetCertificate` for TLS reload if and only if server's `(*tls.Config).Certificates` field is not empty, or `(*tls.ClientHelloInfo).ServerName` is not empty with a valid SNI from the client. Previously, etcd always populates `(*tls.Config).Certificates` on the initial client TLS handshake, as non-empty. Thus, client was always expected to supply a matching SNI in order to pass the TLS verification and to trigger `(*tls.Config).GetCertificate` to reload TLS assets.
-  - However, a certificate whose SAN field does [not include any domain names but only IP addresses](https://github.com/etcd-io/etcd/issues/9541) would request `*tls.ClientHelloInfo` with an empty `ServerName` field, thus failing to trigger the TLS reload on initial TLS handshake; this becomes a problem when expired certificates need to be replaced online.
-  - Now, `(*tls.Config).Certificates` is created empty on initial TLS client handshake, first to trigger `(*tls.Config).GetCertificate`, and then to populate rest of the certificates on every new TLS connection, even when client SNI is empty (e.g. cert only includes IPs).
-
-### etcd server
-
-- Add [`etcd --initial-election-tick-advance`](https://github.com/etcd-io/etcd/pull/9591) flag to configure initial election tick fast-forward.
-  - By default, `etcd --initial-election-tick-advance=true`, then local member fast-forwards election ticks to speed up "initial" leader election trigger.
-  - This benefits the case of larger election ticks. For instance, cross datacenter deployment may require longer election timeout of 10-second. If true, local node does not need wait up to 10-second. Instead, forwards its election ticks to 8-second, and have only 2-second left before leader election.
-  - Major assumptions are that: cluster has no active leader thus advancing ticks enables faster leader election. Or cluster already has an established leader, and rejoining follower is likely to receive heartbeats from the leader after tick advance and before election timeout.
-  - However, when network from leader to rejoining follower is congested, and the follower does not receive leader heartbeat within left election ticks, disruptive election has to happen thus affecting cluster availabilities.
-  - Now, this can be disabled by setting `--initial-election-tick-advance=false`.
-  - Disabling this would slow down initial bootstrap process for cross datacenter deployments. Make tradeoffs by configuring `--initial-election-tick-advance` at the cost of slow initial bootstrap.
-  - If single-node, it advances ticks regardless.
-  - Address [disruptive rejoining follower node](https://github.com/etcd-io/etcd/issues/9333).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.18](https://github.com/etcd-io/etcd/releases/tag/v3.2.18) (2018-03-29)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.17...v3.2.18) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Adjust [election timeout on server restart](https://github.com/etcd-io/etcd/pull/9415) to reduce [disruptive rejoining servers](https://github.com/etcd-io/etcd/issues/9333).
-  - Previously, etcd fast-forwards election ticks on server start, with only one tick left for leader election. This is to speed up start phase, without having to wait until all election ticks elapse. Advancing election ticks is useful for cross datacenter deployments with larger election timeouts. However, it was affecting cluster availability if the last tick elapses before leader contacts the restarted node.
-  - Now, when etcd restarts, it adjusts election ticks with more than one tick left, thus more time for leader to prevent disruptive restart.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add missing [`etcd_network_peer_sent_failures_total` count](https://github.com/etcd-io/etcd/pull/9437).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.17](https://github.com/etcd-io/etcd/releases/tag/v3.2.17) (2018-03-08)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.16...v3.2.17) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Fix [server panic on invalid Election Proclaim/Resign HTTP(S) requests](https://github.com/etcd-io/etcd/pull/9379).
-  - Previously, wrong-formatted HTTP requests to Election API could trigger panic in etcd server.
-  - e.g. `curl -L http://localhost:2379/v3/election/proclaim -X POST -d '{"value":""}'`, `curl -L http://localhost:2379/v3/election/resign -X POST -d '{"value":""}'`.
-- Prevent [overflow by large `TTL` values for `Lease` `Grant`](https://github.com/etcd-io/etcd/pull/9399).
-  - `TTL` parameter to `Grant` request is unit of second.
-  - Leases with too large `TTL` values exceeding `math.MaxInt64` [expire in unexpected ways](https://github.com/etcd-io/etcd/issues/9374).
-  - Server now returns `rpctypes.ErrLeaseTTLTooLarge` to client, when the requested `TTL` is larger than *9,000,000,000 seconds* (which is >285 years).
-  - Again, etcd `Lease` is meant for short-periodic keepalives or sessions, in the range of seconds or minutes. Not for hours or days!
-- Enable etcd server [`raft.Config.CheckQuorum` when starting with `ForceNewCluster`](https://github.com/etcd-io/etcd/pull/9347).
-
-### Proxy v2
-
-- Fix [v2 proxy leaky HTTP requests](https://github.com/etcd-io/etcd/pull/9336).
-
-### Go
-
-- Compile with [*Go 1.8.7*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.16](https://github.com/etcd-io/etcd/releases/tag/v3.2.16) (2018-02-12)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.15...v3.2.16) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Fix [`mvcc` "unsynced" watcher restore operation](https://github.com/etcd-io/etcd/pull/9297).
-  - "unsynced" watcher is watcher that needs to be in sync with events that have happened.
-  - That is, "unsynced" watcher is the slow watcher that was requested on old revision.
-  - "unsynced" watcher restore operation was not correctly populating its underlying watcher group.
-  - Which possibly causes [missing events from "unsynced" watchers](https://github.com/etcd-io/etcd/issues/9086).
-  - A node gets network partitioned with a watcher on a future revision, and falls behind receiving a leader snapshot after partition gets removed. When applying this snapshot, etcd watch storage moves current synced watchers to unsynced since sync watchers might have become stale during network partition. And reset synced watcher group to restart watcher routines. Previously, there was a bug when moving from synced watcher group to unsynced, thus client would miss events when the watcher was requested to the network-partitioned node.
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.15](https://github.com/etcd-io/etcd/releases/tag/v3.2.15) (2018-01-22)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.14...v3.2.15) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Prevent [server panic from member update/add](https://github.com/etcd-io/etcd/pull/9174) with [wrong scheme URLs](https://github.com/etcd-io/etcd/issues/9173).
-- Log [user context cancel errors on stream APIs in debug level with TLS](https://github.com/etcd-io/etcd/pull/9178).
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.14](https://github.com/etcd-io/etcd/releases/tag/v3.2.14) (2018-01-11)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.13...v3.2.14) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Log [user context cancel errors on stream APIs in debug level](https://github.com/etcd-io/etcd/pull/9105).
-
-### etcd server
-
-- Fix [`mvcc/backend.defragdb` nil-pointer dereference on create bucket failure](https://github.com/etcd-io/etcd/pull/9119).
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.13](https://github.com/etcd-io/etcd/releases/tag/v3.2.13) (2018-01-02)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.12...v3.2.13) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Remove [verbose error messages on stream cancel and gRPC info-level logs](https://github.com/etcd-io/etcd/pull/9080) in server-side.
-- Fix [gRPC server panic on `GracefulStop` TLS-enabled server](https://github.com/etcd-io/etcd/pull/8987).
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.12](https://github.com/etcd-io/etcd/releases/tag/v3.2.12) (2017-12-20)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.11...v3.2.12) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Dependency
-
-- Upgrade [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases/tag) from [**`v1.7.4`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.4) to [**`v1.7.5`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.5).
-- Upgrade [`github.com/grpc-ecosystem/grpc-gateway`](https://github.com/grpc-ecosystem/grpc-gateway/releases) from [**`v1.3`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.3) to [**`v1.3.0`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.3.0).
-
-### etcd server
-
-- Fix [error message of `Revision` compactor](https://github.com/etcd-io/etcd/pull/8999) in server-side.
-
-### client v3
-
-- Add [`MaxCallSendMsgSize` and `MaxCallRecvMsgSize`](https://github.com/etcd-io/etcd/pull/9047) fields to [`clientv3.Config`](https://godoc.org/github.com/etcd-io/etcd/clientv3#Config).
-  - Fix [exceeded response size limit error in client-side](https://github.com/etcd-io/etcd/issues/9043).
-  - Address [kubernetes#51099](https://github.com/kubernetes/kubernetes/issues/51099).
-    - In previous versions(v3.2.10, v3.2.11), client response size was limited to only 4 MiB.
-  - `MaxCallSendMsgSize` default value is 2 MiB, if not configured.
-  - `MaxCallRecvMsgSize` default value is `math.MaxInt32`, if not configured.
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.11](https://github.com/etcd-io/etcd/releases/tag/v3.2.11) (2017-12-05)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.10...v3.2.11) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Dependency
-
-- Upgrade [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases/tag) from [**`v1.7.3`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.3) to [**`v1.7.4`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.4).
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- Log [more details on TLS handshake failures](https://github.com/etcd-io/etcd/pull/8952/files).
-
-### client v3
-
-- Fix racey grpc-go's server handler transport `WriteStatus` call to prevent [TLS-enabled etcd server crash](https://github.com/etcd-io/etcd/issues/8904).
-- Add [gRPC RPC failure warnings](https://github.com/etcd-io/etcd/pull/8939) to help debug such issues in the future.
-
-### Documentation
-
-- Remove `--listen-metrics-urls` flag in monitoring document (non-released in `v3.2.x`, planned for `v3.3.x`).
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.10](https://github.com/etcd-io/etcd/releases/tag/v3.2.10) (2017-11-16)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.9...v3.2.10) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Dependency
-
-- Upgrade [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases/tag) from [**`v1.2.1`**](https://github.com/grpc/grpc-go/releases/tag/v1.2.1) to [**`v1.7.3`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.3).
-- Upgrade [`github.com/grpc-ecosystem/grpc-gateway`](https://github.com/grpc-ecosystem/grpc-gateway/releases) from [**`v1.2.0`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.2.0) to [**`v1.3`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.3).
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- Revert [discovery SRV auth `ServerName` with `*.{ROOT_DOMAIN}`](https://github.com/etcd-io/etcd/pull/8651) to support non-wildcard subject alternative names in the certs (see [issue #8445](https://github.com/etcd-io/etcd/issues/8445) for more contexts).
-  - For instance, `etcd --discovery-srv=etcd.local` will only authenticate peers/clients when the provided certs have root domain `etcd.local` (**not `*.etcd.local`**) as an entry in Subject Alternative Name (SAN) field.
-
-### etcd server
-
-- Replace backend key-value database `boltdb/bolt` with [`coreos/bbolt`](https://github.com/coreos/bbolt/releases) to address [backend database size issue](https://github.com/etcd-io/etcd/issues/8009).
-
-### client v3
-
-- Rewrite balancer to handle [network partitions](https://github.com/etcd-io/etcd/issues/8711).
-
-### Go
-
-- Compile with [*Go 1.8.5*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.9](https://github.com/etcd-io/etcd/releases/tag/v3.2.9) (2017-10-06)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.8...v3.2.9) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- Update `golang.org/x/crypto/bcrypt` (see [golang/crypto@6c586e1](https://github.com/golang/crypto/commit/6c586e17d90a7d08bbbc4069984180dce3b04117)).
-- Fix discovery SRV bootstrapping to [authenticate `ServerName` with `*.{ROOT_DOMAIN}`](https://github.com/etcd-io/etcd/pull/8651), in order to support sub-domain wildcard matching (see [issue #8445](https://github.com/etcd-io/etcd/issues/8445) for more contexts).
-  - For instance, `etcd --discovery-srv=etcd.local` will only authenticate peers/clients when the provided certs have root domain `*.etcd.local` as an entry in Subject Alternative Name (SAN) field.
-
-### Go
-
-- Compile with [*Go 1.8.4*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.8](https://github.com/etcd-io/etcd/releases/tag/v3.2.8) (2017-09-29)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.7...v3.2.8) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### client v2
-
-- Fix v2 client failover to next endpoint on mutable operation.
-
-### gRPC Proxy
-
-- Handle [`KeysOnly` flag](https://github.com/etcd-io/etcd/pull/8552).
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.7](https://github.com/etcd-io/etcd/releases/tag/v3.2.7) (2017-09-01)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.6...v3.2.7) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Security, Authentication
-
-- Fix [server-side auth so concurrent auth operations do not return old revision error](https://github.com/etcd-io/etcd/pull/8306).
-
-### client v3
-
-- Fix [`concurrency/stm` Put with serializable snapshot](https://github.com/etcd-io/etcd/pull/8439).
-  - Use store revision from first fetch to resolve write conflicts instead of modified revision.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.6](https://github.com/etcd-io/etcd/releases/tag/v3.2.6) (2017-08-21)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.5...v3.2.6) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Fix watch restore from snapshot.
-- Fix multiple URLs for `--listen-peer-urls` flag.
-- Add `--enable-pprof` flag to etcd configuration file format.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Fix `etcd_debugging_mvcc_keys_total` inconsistency.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.5](https://github.com/etcd-io/etcd/releases/tag/v3.2.5) (2017-08-04)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.4...v3.2.5) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcdctl v3
-
-- Return non-zero exit code on unhealthy `endpoint health`.
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- [Server supports reverse-lookup on wildcard DNS `SAN`](https://github.com/etcd-io/etcd/pull/8281). For instance, if peer cert contains only DNS names (no IP addresses) in Subject Alternative Name (SAN) field, server first reverse-lookups the remote IP address to get a list of names mapping to that address (e.g. `nslookup IPADDR`). Then accepts the connection if those names have a matching name with peer cert's DNS names (either by exact or wildcard match). If none is matched, server forward-lookups each DNS entry in peer cert (e.g. look up `example.default.svc` when the entry is `*.example.default.svc`), and accepts connection only when the host's resolved addresses have the matching IP address with the peer's remote IP address. For example, peer B's CSR (with `cfssl`) SAN field is `["*.example.default.svc", "*.example.default.svc.cluster.local"]` when peer B's remote IP address is `10.138.0.2`. When peer B tries to join the cluster, peer A reverse-lookup the IP `10.138.0.2` to get the list of host names. And either exact or wildcard match the host names with peer B's cert DNS names in Subject Alternative Name (SAN) field. If none of reverse/forward lookups worked, it returns an error `"tls: "10.138.0.2" does not match any of DNSNames ["*.example.default.svc","*.example.default.svc.cluster.local"]`. See [issue#8268](https://github.com/etcd-io/etcd/issues/8268) for more detail.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Fix unreachable `/metrics` endpoint when `--enable-v2=false`.
-
-### gRPC Proxy
-
-- Handle [`PrevKv` flag](https://github.com/etcd-io/etcd/pull/8366).
-
-### Other
-
-- Add container registry `gcr.io/etcd-development/etcd`.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.4](https://github.com/etcd-io/etcd/releases/tag/v3.2.4) (2017-07-19)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.3...v3.2.4) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Do not block on active client stream when stopping server
-
-### gRPC proxy
-
-- Fix gRPC proxy Snapshot RPC error handling
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.3](https://github.com/etcd-io/etcd/releases/tag/v3.2.3) (2017-07-14)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.2...v3.2.3) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### client v3
-
-- Let clients establish unlimited streams
-
-### Other
-
-- Tag docker images with minor versions
-  - e.g. `docker pull quay.io/coreos/etcd:v3.2` to fetch latest v3.2 versions
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.2](https://github.com/etcd-io/etcd/releases/tag/v3.2.2) (2017-07-07)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.1...v3.2.2) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Rate-limit lease revoke on expiration.
-- Extend leases on promote to avoid queueing effect on lease expiration.
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- [Server accepts connections if IP matches, without checking DNS entries](https://github.com/etcd-io/etcd/pull/8223). For instance, if peer cert contains IP addresses and DNS names in Subject Alternative Name (SAN) field, and the remote IP address matches one of those IP addresses, server just accepts connection without further checking the DNS names. For example, peer B's CSR (with `cfssl`) SAN field is `["invalid.domain", "10.138.0.2"]` when peer B's remote IP address is `10.138.0.2` and `invalid.domain` is a invalid host. When peer B tries to join the cluster, peer A successfully authenticates B, since Subject Alternative Name (SAN) field has a valid matching IP address. See [issue#8206](https://github.com/etcd-io/etcd/issues/8206) for more detail.
-
-### etcd server
-
-- Accept connection with matched IP SAN but no DNS match.
-  - Don't check DNS entries in certs if there's a matching IP.
-
-### gRPC gateway
-
-- Use user-provided listen address to connect to gRPC gateway.
-  - `net.Listener` rewrites IPv4 0.0.0.0 to IPv6 [::], breaking IPv6 disabled hosts.
-  - Only v3.2.0, v3.2.1 are affected.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.1](https://github.com/etcd-io/etcd/releases/tag/v3.2.1) (2017-06-23)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.0...v3.2.1) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### etcd server
-
-- Fix backend database in-memory index corruption issue on restore (only 3.2.0 is affected).
-
-### gRPC gateway
-
-- Fix Txn marshaling.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Fix backend database size debugging metrics.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-
-
-## [v3.2.0](https://github.com/etcd-io/etcd/releases/tag/v3.2.0) (2017-06-09)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.1.0...v3.2.0) and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.2 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_2.md).**
-
-### Improved
-
-- Improve backend read concurrency.
-
-### Breaking Changes
-
-- Increased [`--snapshot-count` default value from 10,000 to 100,000](https://github.com/etcd-io/etcd/pull/7160).
-  - Higher snapshot count means it holds Raft entries in memory for longer before discarding old entries.
-  - It is a trade-off between less frequent snapshotting and [higher memory usage](https://github.com/kubernetes/kubernetes/issues/60589#issuecomment-371977156).
-  - User lower `--snapshot-count` value for lower memory usage.
-  - User higher `--snapshot-count` value for better availabilities of slow followers (less frequent snapshots from leader).
-- `clientv3.Lease.TimeToLive` returns `LeaseTimeToLiveResponse.TTL == -1` on lease not found.
-- `clientv3.NewFromConfigFile` is moved to `clientv3/yaml.NewConfig`.
-- `embed.Etcd.Peers` field is now `[]*peerListener`.
-- Rejects domains names for `--listen-peer-urls` and `--listen-client-urls` (3.1 only prints out warnings), since [domain name is invalid for network interface binding](https://github.com/etcd-io/etcd/issues/6336).
-
-### Dependency
-
-- Upgrade [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases) from [**`v1.0.4`**](https://github.com/grpc/grpc-go/releases/tag/v1.0.4) to [**`v1.2.1`**](https://github.com/grpc/grpc-go/releases/tag/v1.2.1).
-- Upgrade [`github.com/grpc-ecosystem/grpc-gateway`](https://github.com/grpc-ecosystem/grpc-gateway/releases) to [**`v1.2.0`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.2.0).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.2.27/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_disk_backend_snapshot_duration_seconds`](https://github.com/etcd-io/etcd/pull/7892)
-- Add `etcd_debugging_server_lease_expired_total` metrics.
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- [TLS certificates get reloaded on every client connection](https://github.com/etcd-io/etcd/pull/7829). This is useful when replacing expiry certs without stopping etcd servers; it can be done by overwriting old certs with new ones. Refreshing certs for every connection should not have too much overhead, but can be improved in the future, with caching layer. Example tests can be found [here](https://github.com/etcd-io/etcd/blob/b041ce5d514a4b4aaeefbffb008f0c7570a18986/integration/v3_grpc_test.go#L1601-L1757).
-- [Server denies incoming peer certs with wrong IP `SAN`](https://github.com/etcd-io/etcd/pull/7687). For instance, if peer cert contains any IP addresses in Subject Alternative Name (SAN) field, server authenticates a peer only when the remote IP address matches one of those IP addresses. This is to prevent unauthorized endpoints from joining the cluster.  For example, peer B's CSR (with `cfssl`) SAN field is `["*.example.default.svc", "*.example.default.svc.cluster.local", "10.138.0.27"]` when peer B's actual IP address is `10.138.0.2`, not `10.138.0.27`. When peer B tries to join the cluster, peer A will reject B with the error `x509: certificate is valid for 10.138.0.27, not 10.138.0.2`, because B's remote IP address does not match the one in Subject Alternative Name (SAN) field.
-- [Server resolves TLS `DNSNames` when checking `SAN`](https://github.com/etcd-io/etcd/pull/7767). For instance, if peer cert contains only DNS names (no IP addresses) in Subject Alternative Name (SAN) field, server authenticates a peer only when forward-lookups (`dig b.com`) on those DNS names have matching IP with the remote IP address.  For example, peer B's CSR (with `cfssl`) SAN field is `["b.com"]` when peer B's remote IP address is `10.138.0.2`. When peer B tries to join the cluster, peer A looks up the incoming host `b.com` to get the list of IP addresses (e.g. `dig b.com`). And rejects B if the list does not contain the IP `10.138.0.2`, with the error `tls: 10.138.0.2 does not match any of DNSNames ["b.com"]`.
-- Auth support JWT token.
-
-### etcd server
-
-- RPCs
-  - Add Election, Lock service.
-- Native client `etcdserver/api/v3client`
-  - client "embedded" in the server.
-- Logging, monitoring
-  - Server warns large snapshot operations.
-- Add `etcd --enable-v2` flag to enable v2 API server.
-  - `etcd --enable-v2=true` by default.
-- Add `etcd --auth-token` flag.
-- v3.2 compactor runs [every hour](https://github.com/etcd-io/etcd/pull/7875).
-  - Compactor only supports periodic compaction.
-  - Compactor continues to record latest revisions every 5-minute.
-  - For every hour, it uses the last revision that was fetched before compaction period, from the revision records that were collected every 5-minute.
-  - That is, for every hour, compactor discards historical data created before compaction period.
-  - The retention window of compaction period moves to next hour.
-  - For instance, when hourly writes are 100 and `--auto-compaction-retention=10`, v3.1 compacts revision 1000, 2000, and 3000 for every 10-hour, while v3.2 compacts revision 1000, 1100, and 1200 for every 1-hour.
-  - If compaction succeeds or requested revision has already been compacted, it resets period timer and removes used compacted revision from historical revision records (e.g. start next revision collect and compaction from previously collected revisions).
-  - If compaction fails, it retries in 5 minutes.
-- Allow snapshot over 512MB.
-
-### client v3
-
-- STM prefetching.
-- Add namespace feature.
-- Add `ErrOldCluster` with server version checking.
-- Translate `WithPrefix()` into `WithFromKey()` for empty key.
-
-### etcdctl v3
-
-- Add `check perf` command.
-- Add `etcdctl --from-key` flag to role grant-permission command.
-- `lock` command takes an optional command to execute.
-
-### gRPC Proxy
-
-- Proxy endpoint discovery.
-- Namespaces.
-- Coalesce lease requests.
-
-### etcd gateway
-
-- Support [DNS SRV priority](https://github.com/etcd-io/etcd/pull/7882) for [smart proxy routing](https://github.com/etcd-io/etcd/issues/4378).
-
-### Other
-
-- v3 client
-  - concurrency package's elections updated to match RPC interfaces.
-  - let client dial endpoints not in the balancer.
-- Release
-  - Annotate acbuild with supports-systemd-notify.
-  - Add `nsswitch.conf` to Docker container image.
-  - Add ppc64le, arm64(experimental) builds.
-
-### Go
-
-- Compile with [*Go 1.8.3*](https://golang.org/doc/devel/release.html#go1.8).
-
-
-<hr>
-

CHANGELOG-3.3.md

@@ -1,734 +0,0 @@
-
-
-Previous change logs can be found at [CHANGELOG-3.2](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.2.md).
-
-
-The minimum recommended etcd versions to run in **production** are 3.1.11+, 3.2.26+, and 3.3.11+.
-
-
-<hr>
-
-
-## [v3.3.14](https://github.com/etcd-io/etcd/releases/tag/v3.3.14) (2019-TBD)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.13...v3.3.14) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### etcd server
-
-- Fix [race condition in `rafthttp` transport pause/resume](https://github.com/etcd-io/etcd/pull/10826).
-
-### client v3
-
-- Fix [gRPC panic "send on closed channel](https://github.com/etcd-io/etcd/issues/9956) by upgrading [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases) from [**`v1.7.5`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.5) to [**`v1.23.0`**](https://github.com/grpc/grpc-go/releases/tag/v1.23.0).
-- Rewrite [client balancer](https://github.com/etcd-io/etcd/pull/9860) with [new gRPC balancer interface](https://github.com/etcd-io/etcd/issues/9106).
-  - Upgrade [gRPC to v1.23.0](https://github.com/etcd-io/etcd/pull/10911).
-  - Improve [client balancer failover against secure endpoints](https://github.com/etcd-io/etcd/pull/10911).
-    - Fix ["kube-apiserver 1.13.x refuses to work when first etcd-server is not available" (kubernetes#72102)](https://github.com/kubernetes/kubernetes/issues/72102).
-
-### etcdctl v3
-
-- Add [`etcdctl endpoint health --write-out` support](https://github.com/etcd-io/etcd/pull/9540).
-  - Previously, [`etcdctl endpoint health --write-out json` did not work](https://github.com/etcd-io/etcd/issues/9532).
-  - The command output is changed. Previously, if endpoint is unreachable, the command output is
-  "\<endpoint\> is unhealthy: failed to connect: \<error message\>". This change unified the error message, all error types
-  now have the same output "\<endpoint\> is unhealthy: failed to commit proposal: \<error message\>".
-- Add [missing newline in `etcdctl endpoint health`](https://github.com/etcd-io/etcd/pull/10793).
-
-
-<hr>
-
-
-## [v3.3.13](https://github.com/etcd-io/etcd/releases/tag/v3.3.13) (2019-05-02)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.12...v3.3.13) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Improved
-
-- Improve [heartbeat send failure logging](https://github.com/etcd-io/etcd/pull/10663).
-- Add [`Verify` function to perform corruption check on WAL contents](https://github.com/etcd-io/etcd/pull/10603).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.readthedocs.io/en/latest/operate.html#v3-3) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Fix bug where [db_compaction_total_duration_milliseconds metric incorrectly measured duration as 0](https://github.com/etcd-io/etcd/pull/10646).
-
-### client v3
-
-- Fix [`(*Client).Endpoints()` method race condition](https://github.com/etcd-io/etcd/pull/10595).
-
-### Package `wal`
-
-- Add [`Verify` function to perform corruption check on WAL contents](https://github.com/etcd-io/etcd/pull/10603).
-
-### Dependency
-
-- Migrate [`github.com/ugorji/go/codec`](https://github.com/ugorji/go/releases) to [**`github.com/json-iterator/go`**](https://github.com/json-iterator/go) (See [#10667](https://github.com/etcd-io/etcd/pull/10667) for more).
-- Migrate [`github.com/ghodss/yaml`](https://github.com/ghodss/yaml/releases) to [**`sigs.k8s.io/yaml`**](https://github.com/kubernetes-sigs/yaml) (See [#10718](https://github.com/etcd-io/etcd/pull/10718) for more).
-
-### Go
-
-- Compile with [*Go 1.10.8*](https://golang.org/doc/devel/release.html#go1.10).
-
-
-<hr>
-
-
-## [v3.3.12](https://github.com/etcd-io/etcd/releases/tag/v3.3.12) (2019-02-07)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.11...v3.3.12) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### etcdctl
-
-- [Strip out insecure endpoints from DNS SRV records when using discovery](https://github.com/etcd-io/etcd/pull/10443) with etcdctl v2
-
-### Go
-
-- Compile with [*Go 1.10.8*](https://golang.org/doc/devel/release.html#go1.10).
-
-
-<hr>
-
-
-## [v3.3.11](https://github.com/etcd-io/etcd/releases/tag/v3.3.11) (2019-01-11)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.10...v3.3.11) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### gRPC Proxy
-
-- Fix [memory leak in cache layer](https://github.com/etcd-io/etcd/pull/10327).
-
-### Security, Authentication
-
-- Disable [CommonName authentication for gRPC-gateway](https://github.com/etcd-io/etcd/pull/10366) gRPC-gateway proxy requests to etcd server use the etcd client server TLS certificate. If that certificate contains CommonName we do not want to use that for authentication as it could lead to permission escalation.
-
-### Go
-
-- Compile with [*Go 1.10.7*](https://golang.org/doc/devel/release.html#go1.10).
-
-
-<hr>
-
-
-## [v3.3.10](https://github.com/etcd-io/etcd/releases/tag/v3.3.10) (2018-10-10)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.9...v3.3.10) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Improved
-
-- Improve ["became inactive" warning log](https://github.com/etcd-io/etcd/pull/10024), which indicates message send to a peer failed.
-- Improve [read index wait timeout warning log](https://github.com/etcd-io/etcd/pull/10026), which indicates that local node might have slow network.
-- Add [gRPC interceptor for debugging logs](https://github.com/etcd-io/etcd/pull/9990); enable `etcd --debug` flag to see per-request debug information.
-- Add [consistency check in snapshot status](https://github.com/etcd-io/etcd/pull/10109). If consistency check on snapshot file fails, `snapshot status` returns `"snapshot file integrity check failed..."` error.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.3.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Improve [`etcd_network_peer_round_trip_time_seconds`](https://github.com/etcd-io/etcd/pull/10155) Prometheus metric to track leader heartbeats.
-  - Previously, it only samples the TCP connection for snapshot messages.
-- Add [`etcd_snap_db_fsync_duration_seconds_count`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_snap_db_save_total_duration_seconds_bucket`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_server_id`](https://github.com/etcd-io/etcd/pull/9998) Prometheus metric.
-- Add [`etcd_server_health_success`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_health_failures`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_read_indexes_failed_total`](https://github.com/etcd-io/etcd/pull/10094) Prometheus metric.
-
-### client v3
-
-- Fix logic on [release lock key if cancelled](https://github.com/etcd-io/etcd/pull/10153) in `clientv3/concurrency` package.
-
-### Go
-
-- Compile with [*Go 1.10.4*](https://golang.org/doc/devel/release.html#go1.10).
-
-
-<hr>
-
-
-## [v3.3.9](https://github.com/etcd-io/etcd/releases/tag/v3.3.9) (2018-07-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.8...v3.3.9) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Improved
-
-- Improve [Raft Read Index timeout warning messages](https://github.com/etcd-io/etcd/pull/9897).
-
-### Security, Authentication
-
-- Compile with [*Go 1.10.3*](https://golang.org/doc/devel/release.html#go1.10) to support [crypto/x509 "Name Constraints"](https://github.com/etcd-io/etcd/issues/9912).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.3.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_go_version`](https://github.com/etcd-io/etcd/pull/9957) Prometheus metric.
-- Add [`etcd_server_heartbeat_send_failures_total`](https://github.com/etcd-io/etcd/pull/9940) Prometheus metric.
-- Add [`etcd_server_slow_apply_total`](https://github.com/etcd-io/etcd/pull/9940) Prometheus metric.
-- Add [`etcd_disk_backend_defrag_duration_seconds`](https://github.com/etcd-io/etcd/pull/9940) Prometheus metric.
-- Add [`etcd_mvcc_hash_duration_seconds`](https://github.com/etcd-io/etcd/pull/9940) Prometheus metric.
-- Add [`etcd_mvcc_hash_rev_duration_seconds`](https://github.com/etcd-io/etcd/pull/9940) Prometheus metric.
-- Add [`etcd_server_slow_read_indexes_total`](https://github.com/etcd-io/etcd/pull/9897) Prometheus metric.
-- Add [`etcd_server_quota_backend_bytes`](https://github.com/etcd-io/etcd/pull/9820) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-- Add [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819) Prometheus metric.
-  - In addition to [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819).
-- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/etcd-io/etcd/pull/9256) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-
-### client v3
-
-- Fix [lease keepalive interval updates when response queue is full](https://github.com/etcd-io/etcd/pull/9952).
-  - If `<-chan *clientv3LeaseKeepAliveResponse` from `clientv3.Lease.KeepAlive` was never consumed or channel is full, client was [sending keepalive request every 500ms](https://github.com/etcd-io/etcd/issues/9911) instead of expected rate of every "TTL / 3" duration.
-
-### Go
-
-- Compile with [*Go 1.10.3*](https://golang.org/doc/devel/release.html#go1.10).
-
-
-<hr>
-
-
-## [v3.3.8](https://github.com/etcd-io/etcd/releases/tag/v3.3.8) (2018-06-15)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.7...v3.3.8) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Improved
-
-- Improve [slow request apply warning log](https://github.com/etcd-io/etcd/pull/9288).
-  - e.g. `read-only range request "key:\"/a\" range_end:\"/b\" " with result "range_response_count:3 size:96" took too long (97.966µs) to execute`.
-  - Redact [request value field](https://github.com/etcd-io/etcd/pull/9822).
-  - Provide [response size](https://github.com/etcd-io/etcd/pull/9826).
-- Add [backoff on watch retries on transient errors](https://github.com/etcd-io/etcd/pull/9840).
-
-### Go
-
-- Compile with [*Go 1.9.7*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.7](https://github.com/etcd-io/etcd/releases/tag/v3.3.7) (2018-06-06)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.6...v3.3.7) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Security, Authentication
-
-- Support TLS cipher suite whitelisting.
-  - To block [weak cipher suites](https://github.com/etcd-io/etcd/issues/8320).
-  - TLS handshake fails when client hello is requested with invalid cipher suites.
-  - Add [`etcd --cipher-suites`](https://github.com/etcd-io/etcd/pull/9801) flag.
-  - If empty, Go auto-populates the list.
-
-### etcdctl v3
-
-- Fix [`etcdctl move-leader` command for TLS-enabled endpoints](https://github.com/etcd-io/etcd/pull/9807).
-
-### Go
-
-- Compile with [*Go 1.9.6*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.6](https://github.com/etcd-io/etcd/releases/tag/v3.3.6) (2018-05-31)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.5...v3.3.6) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### etcd server
-
-- Allow [empty auth token](https://github.com/etcd-io/etcd/pull/9369).
-  - Previously, when auth token is an empty string, it returns [`failed to initialize the etcd server: auth: invalid auth options` error](https://github.com/etcd-io/etcd/issues/9349).
-- Fix [auth storage panic on server lease revoke routine with JWT token](https://github.com/etcd-io/etcd/issues/9695).
-- Fix [`mvcc` server panic from restore operation](https://github.com/etcd-io/etcd/pull/9775).
-  - Let's assume that a watcher had been requested with a future revision X and sent to node A that became network-partitioned thereafter. Meanwhile, cluster makes progress. Then when the partition gets removed, the leader sends a snapshot to node A. Previously if the snapshot's latest revision is still lower than the watch revision X,  **etcd server panicked** during snapshot restore operation.
-  - Now, this server-side panic has been fixed.
-
-### Go
-
-- Compile with [*Go 1.9.6*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.5](https://github.com/etcd-io/etcd/releases/tag/v3.3.5) (2018-05-09)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.4...v3.3.5) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### etcdctl v3
-
-- Fix [`etcdctl watch [key] [range_end] -- [exec-command…]`](https://github.com/etcd-io/etcd/pull/9688) parsing.
-  - Previously,  `ETCDCTL_API=3 ./bin/etcdctl watch foo -- echo watch event received` panicked.
-
-### Go
-
-- Compile with [*Go 1.9.6*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.4](https://github.com/etcd-io/etcd/releases/tag/v3.3.4) (2018-04-24)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.3...v3.3.4) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.3.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_server_is_leader`](https://github.com/etcd-io/etcd/pull/9587) Prometheus metric.
-- Fix [`etcd_debugging_server_lease_expired_total`](https://github.com/etcd-io/etcd/pull/9557) Prometheus metric.
-- Fix [race conditions in v2 server stat collecting](https://github.com/etcd-io/etcd/pull/9562).
-
-### Security, Authentication
-
-- Fix [TLS reload](https://github.com/etcd-io/etcd/pull/9570) when [certificate SAN field only includes IP addresses but no domain names](https://github.com/etcd-io/etcd/issues/9541).
-  - In Go, server calls `(*tls.Config).GetCertificate` for TLS reload if and only if server's `(*tls.Config).Certificates` field is not empty, or `(*tls.ClientHelloInfo).ServerName` is not empty with a valid SNI from the client. Previously, etcd always populates `(*tls.Config).Certificates` on the initial client TLS handshake, as non-empty. Thus, client was always expected to supply a matching SNI in order to pass the TLS verification and to trigger `(*tls.Config).GetCertificate` to reload TLS assets.
-  - However, a certificate whose SAN field does [not include any domain names but only IP addresses](https://github.com/etcd-io/etcd/issues/9541) would request `*tls.ClientHelloInfo` with an empty `ServerName` field, thus failing to trigger the TLS reload on initial TLS handshake; this becomes a problem when expired certificates need to be replaced online.
-  - Now, `(*tls.Config).Certificates` is created empty on initial TLS client handshake, first to trigger `(*tls.Config).GetCertificate`, and then to populate rest of the certificates on every new TLS connection, even when client SNI is empty (e.g. cert only includes IPs).
-
-### etcd server
-
-- Add [`etcd --initial-election-tick-advance`](https://github.com/etcd-io/etcd/pull/9591) flag to configure initial election tick fast-forward.
-  - By default, `etcd --initial-election-tick-advance=true`, then local member fast-forwards election ticks to speed up "initial" leader election trigger.
-  - This benefits the case of larger election ticks. For instance, cross datacenter deployment may require longer election timeout of 10-second. If true, local node does not need wait up to 10-second. Instead, forwards its election ticks to 8-second, and have only 2-second left before leader election.
-  - Major assumptions are that: cluster has no active leader thus advancing ticks enables faster leader election. Or cluster already has an established leader, and rejoining follower is likely to receive heartbeats from the leader after tick advance and before election timeout.
-  - However, when network from leader to rejoining follower is congested, and the follower does not receive leader heartbeat within left election ticks, disruptive election has to happen thus affecting cluster availabilities.
-  - Now, this can be disabled by setting `--initial-election-tick-advance=false`.
-  - Disabling this would slow down initial bootstrap process for cross datacenter deployments. Make tradeoffs by configuring `etcd --initial-election-tick-advance` at the cost of slow initial bootstrap.
-  - If single-node, it advances ticks regardless.
-  - Address [disruptive rejoining follower node](https://github.com/etcd-io/etcd/issues/9333).
-
-### Package `embed`
-
-- Add [`embed.Config.InitialElectionTickAdvance`](https://github.com/etcd-io/etcd/pull/9591) to enable/disable initial election tick fast-forward.
-  - `embed.NewConfig()` would return `*embed.Config` with `InitialElectionTickAdvance` as true by default.
-
-### Go
-
-- Compile with [*Go 1.9.5*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.3](https://github.com/etcd-io/etcd/releases/tag/v3.3.3) (2018-03-29)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.2...v3.3.3) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Improved
-
-- Adjust [election timeout on server restart](https://github.com/etcd-io/etcd/pull/9415) to reduce [disruptive rejoining servers](https://github.com/etcd-io/etcd/issues/9333).
-  - Previously, etcd fast-forwards election ticks on server start, with only one tick left for leader election. This is to speed up start phase, without having to wait until all election ticks elapse. Advancing election ticks is useful for cross datacenter deployments with larger election timeouts. However, it was affecting cluster availability if the last tick elapses before leader contacts the restarted node.
-  - Now, when etcd restarts, it adjusts election ticks with more than one tick left, thus more time for leader to prevent disruptive restart.
-- Adjust [periodic compaction retention window](https://github.com/etcd-io/etcd/pull/9485).
-  - e.g. `etcd --auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000).
-  - e.g. Previously, `etcd --auto-compaction-mode=periodic --auto-compaction-retention=72h` automatically `Compact` with 72-hour retention windown for every 7.2-hour. **Now, `Compact` happens, for every 1-hour but still with 72-hour retention window.**
-  - e.g. Previously, `etcd --auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown for every 3-minute. **Now, `Compact` happens, for every 30-minute but still with 30-minute retention window.**
-  - Periodic compactor keeps recording latest revisions for every compaction period when given period is less than 1-hour, or for every 1-hour when given compaction period is greater than 1-hour (e.g. 1-hour when `etcd --auto-compaction-mode=periodic --auto-compaction-retention=24h`).
-  - For every compaction period or 1-hour, compactor uses the last revision that was fetched before compaction period, to discard historical data.
-  - The retention window of compaction period moves for every given compaction period or hour.
-  - For instance, when hourly writes are 100 and `etcd --auto-compaction-mode=periodic --auto-compaction-retention=24h`, `v3.2.x`, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 2400, 2640, and 2880 for every 2.4-hour, while `v3.3.3` *or later* compacts revision 2400, 2500, 2600 for every 1-hour.
-  - Futhermore, when `etcd --auto-compaction-mode=periodic --auto-compaction-retention=30m` and writes per minute are about 1000, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 30000, 33000, and 36000, for every 3-minute, while `v3.3.3` *or later* compacts revision 30000, 60000, and 90000, for every 30-minute.
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.3.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add missing [`etcd_network_peer_sent_failures_total` count](https://github.com/etcd-io/etcd/pull/9437).
-
-### Go
-
-- Compile with [*Go 1.9.5*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.2](https://github.com/etcd-io/etcd/releases/tag/v3.3.2) (2018-03-08)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.1...v3.3.2) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### etcd server
-
-- Fix [server panic on invalid Election Proclaim/Resign HTTP(S) requests](https://github.com/etcd-io/etcd/pull/9379).
-  - Previously, wrong-formatted HTTP requests to Election API could trigger panic in etcd server.
-  - e.g. `curl -L http://localhost:2379/v3/election/proclaim -X POST -d '{"value":""}'`, `curl -L http://localhost:2379/v3/election/resign -X POST -d '{"value":""}'`.
-- Fix [revision-based compaction retention parsing](https://github.com/etcd-io/etcd/pull/9339).
-  - Previously, `etcd --auto-compaction-mode revision --auto-compaction-retention 1` was [translated to revision retention 3600000000000](https://github.com/etcd-io/etcd/issues/9337).
-  - Now, `etcd --auto-compaction-mode revision --auto-compaction-retention 1` is correctly parsed as revision retention 1.
-- Prevent [overflow by large `TTL` values for `Lease` `Grant`](https://github.com/etcd-io/etcd/pull/9399).
-  - `TTL` parameter to `Grant` request is unit of second.
-  - Leases with too large `TTL` values exceeding `math.MaxInt64` [expire in unexpected ways](https://github.com/etcd-io/etcd/issues/9374).
-  - Server now returns `rpctypes.ErrLeaseTTLTooLarge` to client, when the requested `TTL` is larger than *9,000,000,000 seconds* (which is >285 years).
-  - Again, etcd `Lease` is meant for short-periodic keepalives or sessions, in the range of seconds or minutes. Not for hours or days!
-- Enable etcd server [`raft.Config.CheckQuorum` when starting with `ForceNewCluster`](https://github.com/etcd-io/etcd/pull/9347).
-
-### Proxy v2
-
-- Fix [v2 proxy leaky HTTP requests](https://github.com/etcd-io/etcd/pull/9336).
-
-### Go
-
-- Compile with [*Go 1.9.4*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.1](https://github.com/etcd-io/etcd/releases/tag/v3.3.1) (2018-02-12)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0...v3.3.1) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-### Improved
-
-- Add [warnings on requests taking too long](https://github.com/etcd-io/etcd/pull/9288).
-  - e.g. `etcdserver: read-only range request "key:\"\\000\" range_end:\"\\000\" " took too long [3.389041388s] to execute`
-
-### etcd server
-
-- Fix [`mvcc` "unsynced" watcher restore operation](https://github.com/etcd-io/etcd/pull/9281).
-  - "unsynced" watcher is watcher that needs to be in sync with events that have happened.
-  - That is, "unsynced" watcher is the slow watcher that was requested on old revision.
-  - "unsynced" watcher restore operation was not correctly populating its underlying watcher group.
-  - Which possibly causes [missing events from "unsynced" watchers](https://github.com/etcd-io/etcd/issues/9086).
-  - A node gets network partitioned with a watcher on a future revision, and falls behind receiving a leader snapshot after partition gets removed. When applying this snapshot, etcd watch storage moves current synced watchers to unsynced since sync watchers might have become stale during network partition. And reset synced watcher group to restart watcher routines. Previously, there was a bug when moving from synced watcher group to unsynced, thus client would miss events when the watcher was requested to the network-partitioned node.
-
-### Go
-
-- Compile with [*Go 1.9.4*](https://golang.org/doc/devel/release.html#go1.9).
-
-
-<hr>
-
-
-## [v3.3.0](https://github.com/etcd-io/etcd/releases/tag/v3.3.0) (2018-02-01)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.2.0...v3.3.0) and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.3 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_3.md).**
-
-- [v3.3.0-rc.4](https://github.com/etcd-io/etcd/releases/tag/v3.3.0-rc.4) (2018-01-22), see [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0-rc.3...v3.3.0-rc.4).
-- [v3.3.0-rc.3](https://github.com/etcd-io/etcd/releases/tag/v3.3.0-rc.3) (2018-01-17), see [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0-rc.2...v3.3.0-rc.3).
-- [v3.3.0-rc.2](https://github.com/etcd-io/etcd/releases/tag/v3.3.0-rc.2) (2018-01-11), see [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0-rc.1...v3.3.0-rc.2).
-- [v3.3.0-rc.1](https://github.com/etcd-io/etcd/releases/tag/v3.3.0-rc.1) (2018-01-02), see [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0-rc.0...v3.3.0-rc.1).
-- [v3.3.0-rc.0](https://github.com/etcd-io/etcd/releases/tag/v3.3.0-rc.0) (2017-12-20), see [code changes](https://github.com/etcd-io/etcd/compare/v3.2.0...v3.3.0-rc.0).
-
-### Improved
-
-- Use [`coreos/bbolt`](https://github.com/coreos/bbolt/releases) to replace [`boltdb/bolt`](https://github.com/boltdb/bolt#project-status).
-  - Fix [etcd database size grows until `mvcc: database space exceeded`](https://github.com/etcd-io/etcd/issues/8009).
-- [Support database size larger than 8GiB](https://github.com/etcd-io/etcd/pull/7525) (8GiB is now a suggested maximum size for normal environments)
-- [Reduce memory allocation](https://github.com/etcd-io/etcd/pull/8428) on [Range operations](https://github.com/etcd-io/etcd/pull/8475).
-- [Rate limit](https://github.com/etcd-io/etcd/pull/8099) and [randomize](https://github.com/etcd-io/etcd/pull/8101) lease revoke on restart or leader elections.
-  - Prevent [spikes in Raft proposal rate](https://github.com/etcd-io/etcd/issues/8096).
-- Support `clientv3` balancer failover under [network faults/partitions](https://github.com/etcd-io/etcd/issues/8711).
-- Better warning on [mismatched `etcd --initial-cluster`](https://github.com/etcd-io/etcd/pull/8083) flag.
-  - etcd compares `etcd --initial-advertise-peer-urls` against corresponding `etcd --initial-cluster` URLs with forward-lookup.
-  - If resolved IP addresses of `etcd --initial-advertise-peer-urls` and `etcd --initial-cluster` do not match (e.g. [due to DNS error](https://github.com/etcd-io/etcd/pull/9210)), etcd will exit with errors.
-    - v3.2 error: `etcd --initial-cluster must include s1=https://s1.test:2380 given --initial-advertise-peer-urls=https://s1.test:2380`.
-    - v3.3 error: `failed to resolve https://s1.test:2380 to match --initial-cluster=s1=https://s1.test:2380 (failed to resolve "https://s1.test:2380" (error ...))`.
-
-### Breaking Changes
-
-- Require [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases) [**`v1.7.4`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.4) or [**`v1.7.5`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.5).
-  - Deprecate [`metadata.Incoming/OutgoingContext`](https://github.com/etcd-io/etcd/pull/7896).
-  - Deprecate `grpclog.Logger`, upgrade to [`grpclog.LoggerV2`](https://github.com/etcd-io/etcd/pull/8533).
-  - Deprecate [`grpc.ErrClientConnTimeout`](https://github.com/etcd-io/etcd/pull/8505) errors in `clientv3`.
-  - Use [`MaxRecvMsgSize` and `MaxSendMsgSize`](https://github.com/etcd-io/etcd/pull/8437) to limit message size, in etcd server.
-- Translate [gRPC status error in v3 client `Snapshot` API](https://github.com/etcd-io/etcd/pull/9038).
-- v3 `etcdctl` [`lease timetolive LEASE_ID`](https://github.com/etcd-io/etcd/issues/9028) on expired lease now prints [`"lease LEASE_ID already expired"`](https://github.com/etcd-io/etcd/pull/9047).
-  - <=3.2 prints `"lease LEASE_ID granted with TTL(0s), remaining(-1s)"`.
-- Replace [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway) endpoint `/v3alpha` with [`/v3beta`](https://github.com/etcd-io/etcd/pull/8880).
-  - To deprecate [`/v3alpha`](https://github.com/etcd-io/etcd/issues/8125) in v3.4.
-  - In v3.3, `curl -L http://localhost:2379/v3alpha/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` still works as a fallback to `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'`, but `curl -L http://localhost:2379/v3alpha/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` won't work in v3.4. Use `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` instead.
-- Change `etcd --auto-compaction-retention` flag to [accept string values](https://github.com/etcd-io/etcd/pull/8563) with [finer granularity](https://github.com/etcd-io/etcd/issues/8503).
-  - Now that `etcd --auto-compaction-retention` accepts string values, etcd configuration YAML file `auto-compaction-retention` field must be changed to `string` type.
-  - Previously, `--config-file etcd.config.yaml` can have `auto-compaction-retention: 24` field, now must be `auto-compaction-retention: "24"` or `auto-compaction-retention: "24h"`.
-  - If configured as `etcd --auto-compaction-mode periodic --auto-compaction-retention "24h"`, the time duration value for `etcd --auto-compaction-retention` flag must be valid for [`time.ParseDuration`](https://golang.org/pkg/time/#ParseDuration) function in Go.
-
-### Dependency
-
-- Upgrade [`boltdb/bolt`](https://github.com/boltdb/bolt#project-status) from [**`v1.3.0`**](https://github.com/boltdb/bolt/releases/tag/v1.3.0) to [`coreos/bbolt`](https://github.com/coreos/bbolt/releases) [**`v1.3.1-coreos.6`**](https://github.com/coreos/bbolt/releases/tag/v1.3.1-coreos.6).
-- Upgrade [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases) from [**`v1.2.1`**](https://github.com/grpc/grpc-go/releases/tag/v1.2.1) to [**`v1.7.5`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.5).
-- Upgrade [`github.com/ugorji/go/codec`](https://github.com/ugorji/go) to [**`v1.1`**](https://github.com/ugorji/go/releases/tag/v1.1), and [regenerate v2 `client`](https://github.com/etcd-io/etcd/pull/8721).
-- Upgrade [`github.com/ugorji/go/codec`](https://github.com/ugorji/go) to [**`ugorji/go@54210f4e0`**](https://github.com/ugorji/go/commit/54210f4e076c57f351166f0ed60e67d3fca57a36), and [regenerate v2 `client`](https://github.com/etcd-io/etcd/pull/8574).
-- Upgrade [`github.com/grpc-ecosystem/grpc-gateway`](https://github.com/grpc-ecosystem/grpc-gateway/releases) from [**`v1.2.2`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.2.2) to [**`v1.3.0`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.3.0).
-- Upgrade [`golang.org/x/crypto/bcrypt`](https://github.com/golang/crypto) to [**`golang/crypto@6c586e17d`**](https://github.com/golang/crypto/commit/6c586e17d90a7d08bbbc4069984180dce3b04117).
-
-### Metrics, Monitoring
-
-See [List of metrics](https://etcd.io/docs/v3.3.12/metrics/) for all metrics per release.
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd --listen-metrics-urls`](https://github.com/etcd-io/etcd/pull/8242) flag for additional `/metrics` and `/health` endpoints.
-  - Useful for [bypassing critical APIs when monitoring etcd](https://github.com/etcd-io/etcd/issues/8060).
-- Add [`etcd_server_version`](https://github.com/etcd-io/etcd/pull/8960) Prometheus metric.
-  - To replace [Kubernetes `etcd-version-monitor`](https://github.com/etcd-io/etcd/issues/8948).
-- Add [`etcd_debugging_mvcc_db_compaction_keys_total`](https://github.com/etcd-io/etcd/pull/8280) Prometheus metric.
-- Add [`etcd_debugging_server_lease_expired_total`](https://github.com/etcd-io/etcd/pull/8064) Prometheus metric.
-  - To improve [lease revoke monitoring](https://github.com/etcd-io/etcd/issues/8050).
-- Document [Prometheus 2.0 rules](https://github.com/etcd-io/etcd/pull/8879).
-- Initialize gRPC server [metrics with zero values](https://github.com/etcd-io/etcd/pull/8878).
-- Fix [range/put/delete operation metrics](https://github.com/etcd-io/etcd/pull/8054) with transaction.
-  - `etcd_debugging_mvcc_range_total`
-  - `etcd_debugging_mvcc_put_total`
-  - `etcd_debugging_mvcc_delete_total`
-  - `etcd_debugging_mvcc_txn_total`
-- Fix [`etcd_debugging_mvcc_keys_total`](https://github.com/etcd-io/etcd/pull/8390) on restore.
-- Fix [`etcd_debugging_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/8120) on restore.
-  - Also change to [`prometheus.NewGaugeFunc`](https://github.com/etcd-io/etcd/pull/8150).
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- Add [CRL based connection rejection](https://github.com/etcd-io/etcd/pull/8124) to manage [revoked certs](https://github.com/etcd-io/etcd/issues/4034).
-- Document [TLS authentication changes](https://github.com/etcd-io/etcd/pull/8895).
-  - [Server accepts connections if IP matches, without checking DNS entries](https://github.com/etcd-io/etcd/pull/8223). For instance, if peer cert contains IP addresses and DNS names in Subject Alternative Name (SAN) field, and the remote IP address matches one of those IP addresses, server just accepts connection without further checking the DNS names.
-  - [Server supports reverse-lookup on wildcard DNS `SAN`](https://github.com/etcd-io/etcd/pull/8281). For instance, if peer cert contains only DNS names (no IP addresses) in Subject Alternative Name (SAN) field, server first reverse-lookups the remote IP address to get a list of names mapping to that address (e.g. `nslookup IPADDR`). Then accepts the connection if those names have a matching name with peer cert's DNS names (either by exact or wildcard match). If none is matched, server forward-lookups each DNS entry in peer cert (e.g. look up `example.default.svc` when the entry is `*.example.default.svc`), and accepts connection only when the host's resolved addresses have the matching IP address with the peer's remote IP address.
-- Add [`etcd --peer-cert-allowed-cn`](https://github.com/etcd-io/etcd/pull/8616) flag.
-  - To support [CommonName(CN) based auth](https://github.com/etcd-io/etcd/issues/8262) for inter peer connection.
-- [Swap priority](https://github.com/etcd-io/etcd/pull/8594) of cert CommonName(CN) and username + password.
-  - To address ["username and password specified in the request should take priority over CN in the cert"](https://github.com/etcd-io/etcd/issues/8584).
-- Protect [lease revoke with auth](https://github.com/etcd-io/etcd/pull/8031).
-- Provide user's role on [auth permission error](https://github.com/etcd-io/etcd/pull/8164).
-- Fix [auth store panic with disabled token](https://github.com/etcd-io/etcd/pull/8695).
-
-### etcd server
-
-- Add [`etcd --experimental-initial-corrupt-check`](https://github.com/etcd-io/etcd/pull/8554) flag to [check cluster database hashes before serving client/peer traffic](https://github.com/etcd-io/etcd/issues/8313).
-  - `etcd --experimental-initial-corrupt-check=false` by default.
-  - v3.4 will enable `--initial-corrupt-check=true` by default.
-- Add [`etcd --experimental-corrupt-check-time`](https://github.com/etcd-io/etcd/pull/8420) flag to [raise corrupt alarm monitoring](https://github.com/etcd-io/etcd/issues/7125).
-  - `etcd --experimental-corrupt-check-time=0s` disabled by default.
-- Add [`etcd --experimental-enable-v2v3`](https://github.com/etcd-io/etcd/pull/8407) flag to [emulate v2 API with v3](https://github.com/etcd-io/etcd/issues/6925).
-  - `etcd --experimental-enable-v2v3=false` by default.
-- Add [`etcd --max-txn-ops`](https://github.com/etcd-io/etcd/pull/7976) flag to [configure maximum number operations in transaction](https://github.com/etcd-io/etcd/issues/7826).
-- Add [`etcd --max-request-bytes`](https://github.com/etcd-io/etcd/pull/7968) flag to [configure maximum client request size](https://github.com/etcd-io/etcd/issues/7923).
-  - If not configured, it defaults to 1.5 MiB.
-- Add [`etcd --client-crl-file`, `--peer-crl-file`](https://github.com/etcd-io/etcd/pull/8124) flags for [Certificate revocation list](https://github.com/etcd-io/etcd/issues/4034).
-- Add [`etcd --peer-cert-allowed-cn`](https://github.com/etcd-io/etcd/pull/8616) flag to support [CN-based auth for inter-peer connection](https://github.com/etcd-io/etcd/issues/8262).
-- Add [`etcd --listen-metrics-urls`](https://github.com/etcd-io/etcd/pull/8242) flag for additional `/metrics` and `/health` endpoints.
-  - Support [additional (non) TLS `/metrics` endpoints for a TLS-enabled cluster](https://github.com/etcd-io/etcd/pull/8282).
-  - e.g. `etcd --listen-metrics-urls=https://localhost:2378,http://localhost:9379` to serve `/metrics` and `/health` on secure port 2378 and insecure port 9379.
-  - Useful for [bypassing critical APIs when monitoring etcd](https://github.com/etcd-io/etcd/issues/8060).
-- Add [`etcd --auto-compaction-mode`](https://github.com/etcd-io/etcd/pull/8123) flag to [support revision-based compaction](https://github.com/etcd-io/etcd/issues/8098).
-- Change `etcd --auto-compaction-retention` flag to [accept string values](https://github.com/etcd-io/etcd/pull/8563) with [finer granularity](https://github.com/etcd-io/etcd/issues/8503).
-  - Now that `etcd --auto-compaction-retention` accepts string values, etcd configuration YAML file `auto-compaction-retention` field must be changed to `string` type.
-  - Previously, `etcd --config-file etcd.config.yaml` can have `auto-compaction-retention: 24` field, now must be `auto-compaction-retention: "24"` or `auto-compaction-retention: "24h"`.
-  - If configured as `--auto-compaction-mode periodic --auto-compaction-retention "24h"`, the time duration value for `etcd --auto-compaction-retention` flag must be valid for [`time.ParseDuration`](https://golang.org/pkg/time/#ParseDuration) function in Go.
-  - e.g. `etcd --auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000).
-  - e.g. `etcd --auto-compaction-mode=periodic --auto-compaction-retention=72h` automatically `Compact` with 72-hour retention windown, for every 7.2-hour.
-  - e.g. `etcd --auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown, for every 3-minute.
-  - Periodic compactor continues to record latest revisions for every 1/10 of given compaction period (e.g. 1-hour when `etcd --auto-compaction-mode=periodic --auto-compaction-retention=10h`).
-  - For every 1/10 of given compaction period, compactor uses the last revision that was fetched before compaction period, to discard historical data.
-  - The retention window of compaction period moves for every 1/10 of given compaction period.
-  - For instance, when hourly writes are 100 and `--auto-compaction-retention=10`, v3.1 compacts revision 1000, 2000, and 3000 for every 10-hour, while v3.2.x, v3.3.0, v3.3.1, and v3.3.2 compact revision 1000, 1100, and 1200 for every 1-hour. Futhermore, when writes per minute are 1000, v3.3.0, v3.3.1, and v3.3.2 with `--auto-compaction-mode=periodic --auto-compaction-retention=30m` compact revision 30000, 33000, and 36000, for every 3-minute with more finer granularity.
-  - Whether compaction succeeds or not, this process repeats for every 1/10 of given compaction period. If compaction succeeds, it just removes compacted revision from historical revision records.
-- Add [`etcd --grpc-keepalive-min-time`, `etcd --grpc-keepalive-interval`, `etcd --grpc-keepalive-timeout`](https://github.com/etcd-io/etcd/pull/8535) flags to configure server-side keepalive policies.
-- Serve [`/health` endpoint as unhealthy](https://github.com/etcd-io/etcd/pull/8272) when [alarm (e.g. `NOSPACE`) is raised or there's no leader](https://github.com/etcd-io/etcd/issues/8207).
-  - Define [`etcdhttp.Health`](https://godoc.org/github.com/coreos/etcd/etcdserver/api/etcdhttp#Health) struct with JSON encoder.
-  - Note that `"health"` field is [`string` type, not `bool`](https://github.com/etcd-io/etcd/pull/9143).
-    - e.g. `{"health":"false"}`, `{"health":"true"}`
-  - [Remove `"errors"` field](https://github.com/etcd-io/etcd/pull/9162) since `v3.3.0-rc.3` (did exist only in `v3.3.0-rc.0`, `v3.3.0-rc.1`, `v3.3.0-rc.2`).
-- Move [logging setup to embed package](https://github.com/etcd-io/etcd/pull/8810)
-  - Disable gRPC server info-level logs by default (can be enabled with `etcd --debug` flag).
-- Use [monotonic time in Go 1.9](https://github.com/etcd-io/etcd/pull/8507) for `lease` package.
-- Warn on [empty hosts in advertise URLs](https://github.com/etcd-io/etcd/pull/8384).
-  - Address [advertise client URLs accepts empty hosts](https://github.com/etcd-io/etcd/issues/8379).
-  - etcd v3.4 will exit on this error.
-    - e.g. `etcd --advertise-client-urls=http://:2379`.
-- Warn on [shadowed environment variables](https://github.com/etcd-io/etcd/pull/8385).
-  - Address [error on shadowed environment variables](https://github.com/etcd-io/etcd/issues/8380).
-  - etcd v3.4 will exit on this error.
-
-### API
-
-- Support [ranges in transaction comparisons](https://github.com/etcd-io/etcd/pull/8025) for [disconnected linearized reads](https://github.com/etcd-io/etcd/issues/7924).
-- Add [nested transactions](https://github.com/etcd-io/etcd/pull/8102) to extend [proxy use cases](https://github.com/etcd-io/etcd/issues/7857).
-- Add [lease comparison target in transaction](https://github.com/etcd-io/etcd/pull/8324).
-- Add [lease list](https://github.com/etcd-io/etcd/pull/8358).
-- Add [hash by revision](https://github.com/etcd-io/etcd/pull/8263) for [better corruption checking against boltdb](https://github.com/etcd-io/etcd/issues/8016).
-
-### client v3
-
-- Add [health balancer](https://github.com/etcd-io/etcd/pull/8545) to fix [watch API hangs](https://github.com/etcd-io/etcd/issues/7247), improve [endpoint switch under network faults](https://github.com/etcd-io/etcd/issues/7941).
-- [Refactor balancer](https://github.com/etcd-io/etcd/pull/8840) and add [client-side keepalive pings](https://github.com/etcd-io/etcd/pull/8199) to handle [network partitions](https://github.com/etcd-io/etcd/issues/8711).
-- Add [`MaxCallSendMsgSize` and `MaxCallRecvMsgSize`](https://github.com/etcd-io/etcd/pull/9047) fields to [`clientv3.Config`](https://godoc.org/github.com/coreos/etcd/clientv3#Config).
-  - Fix [exceeded response size limit error in client-side](https://github.com/etcd-io/etcd/issues/9043).
-  - Address [kubernetes#51099](https://github.com/kubernetes/kubernetes/issues/51099).
-    - In previous versions(v3.2.10, v3.2.11), client response size was limited to only 4 MiB.
-  - `MaxCallSendMsgSize` default value is 2 MiB, if not configured.
-  - `MaxCallRecvMsgSize` default value is `math.MaxInt32`, if not configured.
-- Accept [`Compare_LEASE`](https://github.com/etcd-io/etcd/pull/8324) in [`clientv3.Compare`](https://godoc.org/github.com/coreos/etcd/clientv3#Compare).
-- Add [`LeaseValue` helper](https://github.com/etcd-io/etcd/pull/8488) to `Cmp` `LeaseID` values in `Txn`.
-- Add [`MoveLeader`](https://github.com/etcd-io/etcd/pull/8153) to `Maintenance`.
-- Add [`HashKV`](https://github.com/etcd-io/etcd/pull/8351) to `Maintenance`.
-- Add [`Leases`](https://github.com/etcd-io/etcd/pull/8358) to `Lease`.
-- Add [`clientv3/ordering`](https://github.com/etcd-io/etcd/pull/8092) for enforce [ordering in serialized requests](https://github.com/etcd-io/etcd/issues/7623).
-- Fix ["put at-most-once" violation](https://github.com/etcd-io/etcd/pull/8335).
-- Fix [`WatchResponse.Canceled`](https://github.com/etcd-io/etcd/pull/8283) on [compacted watch request](https://github.com/etcd-io/etcd/issues/8231).
-- Fix [`concurrency/stm` `Put` with serializable snapshot](https://github.com/etcd-io/etcd/pull/8439).
-  - Use store revision from first fetch to resolve write conflicts instead of modified revision.
-
-### etcdctl v3
-
-- Add [`etcdctl --discovery-srv`](https://github.com/etcd-io/etcd/pull/8462) flag.
-- Add [`etcdctl --keepalive-time`, `--keepalive-timeout`](https://github.com/etcd-io/etcd/pull/8663) flags.
-- Add [`etcdctl lease list`](https://github.com/etcd-io/etcd/pull/8358) command.
-- Add [`etcdctl lease keep-alive --once`](https://github.com/etcd-io/etcd/pull/8775) flag.
-- Make [`lease timetolive LEASE_ID`](https://github.com/etcd-io/etcd/issues/9028) on expired lease print [`lease LEASE_ID already expired`](https://github.com/etcd-io/etcd/pull/9047).
-  - <=3.2 prints `lease LEASE_ID granted with TTL(0s), remaining(-1s)`.
-- Add [`etcdctl snapshot restore --wal-dir`](https://github.com/etcd-io/etcd/pull/9124) flag.
-- Add [`etcdctl defrag --data-dir`](https://github.com/etcd-io/etcd/pull/8367) flag.
-- Add [`etcdctl move-leader`](https://github.com/etcd-io/etcd/pull/8153) command.
-- Add [`etcdctl endpoint hashkv`](https://github.com/etcd-io/etcd/pull/8351) command.
-- Add [`etcdctl endpoint --cluster`](https://github.com/etcd-io/etcd/pull/8143) flag, equivalent to [v2 `etcdctl cluster-health`](https://github.com/etcd-io/etcd/issues/8117).
-- Make `etcdctl endpoint health` command terminate with [non-zero exit code on unhealthy status](https://github.com/etcd-io/etcd/pull/8342).
-- Add [`etcdctl lock --ttl`](https://github.com/etcd-io/etcd/pull/8370) flag.
-- Support [`etcdctl watch [key] [range_end] -- [exec-command…]`](https://github.com/etcd-io/etcd/pull/8919), equivalent to [v2 `etcdctl exec-watch`](https://github.com/etcd-io/etcd/issues/8814).
-  - Make `etcdctl watch -- [exec-command]` set environmental variables [`ETCD_WATCH_REVISION`, `ETCD_WATCH_EVENT_TYPE`, `ETCD_WATCH_KEY`, `ETCD_WATCH_VALUE`](https://github.com/etcd-io/etcd/pull/9142) for each event.
-- Support [`etcdctl watch` with environmental variables `ETCDCTL_WATCH_KEY` and `ETCDCTL_WATCH_RANGE_END`](https://github.com/etcd-io/etcd/pull/9142).
-- Enable [`clientv3.WithRequireLeader(context.Context)` for `watch`](https://github.com/etcd-io/etcd/pull/8672) command.
-- Print [`"del"` instead of `"delete"`](https://github.com/etcd-io/etcd/pull/8297) in `txn` interactive mode.
-- Print [`ETCD_INITIAL_ADVERTISE_PEER_URLS` in `member add`](https://github.com/etcd-io/etcd/pull/8332).
-
-### etcdctl v3
-
-- Handle [empty key permission](https://github.com/etcd-io/etcd/pull/8514) in `etcdctl`.
-
-### etcdctl v2
-
-- Add [`etcdctl backup --with-v3`](https://github.com/etcd-io/etcd/pull/8479) flag.
-
-### gRPC Proxy
-
-- Add [`grpc-proxy start --experimental-leasing-prefix`](https://github.com/etcd-io/etcd/pull/8341) flag.
-  - For disconnected linearized reads.
-  - Based on [V system leasing](https://github.com/etcd-io/etcd/issues/6065).
-  - See ["Disconnected consistent reads with etcd" blog post](https://coreos.com/blog/coreos-labs-disconnected-consistent-reads-with-etcd).
-- Add [`grpc-proxy start --experimental-serializable-ordering`](https://github.com/etcd-io/etcd/pull/8315) flag.
-  - To ensure serializable reads have monotonically increasing store revisions across endpoints.
-- Add [`grpc-proxy start --metrics-addr`](https://github.com/etcd-io/etcd/pull/8242) flag for an additional `/metrics` endpoint.
-  - Set `--metrics-addr=http://[HOST]:9379` to serve `/metrics` in insecure port 9379.
-- Serve [`/health` endpoint in grpc-proxy](https://github.com/etcd-io/etcd/pull/8322).
-- Add [`grpc-proxy start --debug`](https://github.com/etcd-io/etcd/pull/8994) flag.
-- Add [`grpc-proxy start --max-send-bytes`](https://github.com/etcd-io/etcd/pull/9250) flag to [configure maximum client request size](https://github.com/etcd-io/etcd/issues/7923).
-- Add [`grpc-proxy start --max-recv-bytes`](https://github.com/etcd-io/etcd/pull/9250) flag to [configure maximum client request size](https://github.com/etcd-io/etcd/issues/7923).
-- Fix [Snapshot API error handling](https://github.com/etcd-io/etcd/commit/dbd16d52fbf81e5fd806d21ff5e9148d5bf203ab).
-- Fix [KV API `PrevKv` flag handling](https://github.com/etcd-io/etcd/pull/8366).
-- Fix [KV API `KeysOnly` flag handling](https://github.com/etcd-io/etcd/pull/8552).
-
-### gRPC gateway
-
-- Replace [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway) endpoint `/v3alpha` with [`/v3beta`](https://github.com/etcd-io/etcd/pull/8880).
-  - To deprecate [`/v3alpha`](https://github.com/etcd-io/etcd/issues/8125) in v3.4.
-  - In v3.3, `curl -L http://localhost:2379/v3alpha/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` still works as a fallback to `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'`, but `curl -L http://localhost:2379/v3alpha/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` won't work in v3.4. Use `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` instead.
-- Support ["authorization" token](https://github.com/etcd-io/etcd/pull/7999).
-- Support [websocket for bi-directional streams](https://github.com/etcd-io/etcd/pull/8257).
-  - Fix [`Watch` API with gRPC gateway](https://github.com/etcd-io/etcd/issues/8237).
-- Upgrade gRPC gateway to [v1.3.0](https://github.com/etcd-io/etcd/issues/8838).
-
-### etcd server
-
-- Fix [backend database in-memory index corruption](https://github.com/etcd-io/etcd/pull/8127) issue on restore (only 3.2.0 is affected).
-- Fix [watch restore from snapshot](https://github.com/etcd-io/etcd/pull/8427).
-- Fix [`mvcc/backend.defragdb` nil-pointer dereference on create bucket failure](https://github.com/etcd-io/etcd/pull/9119).
-- Fix [server crash](https://github.com/etcd-io/etcd/pull/8010) on [invalid transaction request from gRPC gateway](https://github.com/etcd-io/etcd/issues/7889).
-- Prevent [server panic from member update/add](https://github.com/etcd-io/etcd/pull/9174) with [wrong scheme URLs](https://github.com/etcd-io/etcd/issues/9173).
-- Make [peer dial timeout longer](https://github.com/etcd-io/etcd/pull/8599).
-  - See [coreos/etcd-operator#1300](https://github.com/etcd-io/etcd-operator/issues/1300) for more detail.
-- Make server [wait up to request time-out](https://github.com/etcd-io/etcd/pull/8267) with [pending RPCs](https://github.com/etcd-io/etcd/issues/8224).
-- Fix [`grpc.Server` panic on `GracefulStop`](https://github.com/etcd-io/etcd/pull/8987) with [TLS-enabled server](https://github.com/etcd-io/etcd/issues/8916).
-- Fix ["multiple peer URLs cannot start" issue](https://github.com/etcd-io/etcd/issues/8383).
-- Fix server-side auth so [concurrent auth operations do not return old revision error](https://github.com/etcd-io/etcd/pull/8442).
-- Handle [WAL renaming failure on Windows](https://github.com/etcd-io/etcd/pull/8286).
-- Upgrade [`coreos/go-systemd`](https://github.com/coreos/go-systemd/releases) to `v15` (see https://github.com/coreos/go-systemd/releases/tag/v15).
-- [Put back `/v2/machines`](https://github.com/etcd-io/etcd/pull/8062) endpoint for python-etcd wrapper.
-
-### client v2
-
-- [Fail-over v2 client](https://github.com/etcd-io/etcd/pull/8519) to next endpoint on [oneshot failure](https://github.com/etcd-io/etcd/issues/8515).
-
-### Package `raft`
-
-- Add [non-voting member](https://github.com/etcd-io/etcd/pull/8751).
-  - To implement [Raft thesis 4.2.1 Catching up new servers](https://github.com/etcd-io/etcd/issues/8568).
-  - `Learner` node does not vote or promote itself.
-
-### Other
-
-- Support previous two minor versions (see our [new release policy](https://github.com/etcd-io/etcd/pull/8805)).
-- `v3.3.x` is the last release cycle that supports `ACI`.
-  - [AppC was officially suspended](https://github.com/appc/spec#-disclaimer-), as of late 2016.
-  - [`acbuild`](https://github.com/containers/build#this-project-is-currently-unmaintained) is not maintained anymore.
-  - `*.aci` files won't be available from etcd v3.4 release.
-- Add container registry [`gcr.io/etcd-development/etcd`](https://gcr.io/etcd-development/etcd).
-  - [quay.io/coreos/etcd](https://quay.io/coreos/etcd) is still supported as secondary.
-
-### Go
-
-- Require [*Go 1.9+*](https://github.com/etcd-io/etcd/issues/6174).
-- Compile with [*Go 1.9.3*](https://golang.org/doc/devel/release.html#go1.9).
-- Deprecate [`golang.org/x/net/context`](https://github.com/etcd-io/etcd/pull/8511).
-
-
-<hr>
-

CHANGELOG-3.4.md

@@ -1,557 +0,0 @@
-
-
-Previous change logs can be found at [CHANGELOG-3.3](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.3.md).
-
-
-<hr>
-
-
-## v3.4.0 (2019-08-30)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.3.0...v3.4.0) and [v3.4 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_4.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.4 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_4.md).**
-
-### Documentation
-
-- etcd now has a new website! Please visit https://etcd.io.
-
-### Improved
-
-- Add Raft learner: [etcd#10725](https://github.com/etcd-io/etcd/pull/10725), [etcd#10727](https://github.com/etcd-io/etcd/pull/10727), [etcd#10730](https://github.com/etcd-io/etcd/pull/10730).
-  - User guide: [runtime-configuration document](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/runtime-configuration.md#add-a-new-member-as-learner).
-  - API change: [API reference document](https://github.com/etcd-io/etcd/blob/master/Documentation/dev-guide/api_reference_v3.md).
-  - More details on implementation: [learner design document](https://github.com/etcd-io/etcd/blob/master/Documentation/learning/design-learner.md) and [implementation task list](https://github.com/etcd-io/etcd/issues/10537).
-- Rewrite [client balancer](https://github.com/etcd-io/etcd/pull/9860) with [new gRPC balancer interface](https://github.com/etcd-io/etcd/issues/9106).
-  - Upgrade [gRPC to v1.23.0](https://github.com/etcd-io/etcd/pull/10911).
-  - Improve [client balancer failover against secure endpoints](https://github.com/etcd-io/etcd/pull/10911).
-    - Fix ["kube-apiserver 1.13.x refuses to work when first etcd-server is not available" (kubernetes#72102)](https://github.com/kubernetes/kubernetes/issues/72102).
-  - Fix [gRPC panic "send on closed channel](https://github.com/etcd-io/etcd/issues/9956).
-- Add [backoff on watch retries on transient errors](https://github.com/etcd-io/etcd/pull/9840).
-- Add [jitter to watch progress notify](https://github.com/etcd-io/etcd/pull/9278) to prevent [spikes in `etcd_network_client_grpc_sent_bytes_total`](https://github.com/etcd-io/etcd/issues/9246).
-- Improve [read index wait timeout warning log](https://github.com/etcd-io/etcd/pull/10026), which indicates that local node might have slow network.
-- Improve [slow request apply warning log](https://github.com/etcd-io/etcd/pull/9288).
-  - e.g. `read-only range request "key:\"/a\" range_end:\"/b\" " with result "range_response_count:3 size:96" took too long (97.966µs) to execute`.
-  - Redact [request value field](https://github.com/etcd-io/etcd/pull/9822).
-  - Provide [response size](https://github.com/etcd-io/etcd/pull/9826).
-- Improve ["became inactive" warning log](https://github.com/etcd-io/etcd/pull/10024), which indicates message send to a peer failed.
-- Improve [TLS setup error logging](https://github.com/etcd-io/etcd/pull/9518) to help debug [TLS-enabled cluster configuring issues](https://github.com/etcd-io/etcd/issues/9400).
-- Improve [long-running concurrent read transactions under light write workloads](https://github.com/etcd-io/etcd/pull/9296).
-  - Previously, periodic commit on pending writes blocks incoming read transactions, even if there is no pending write.
-  - Now, periodic commit operation does not block concurrent read transactions, thus improves long-running read transaction performance.
-  - Rebased [etcd#10523](https://github.com/etcd-io/etcd/pull/10523).
-- Improve [Raft Read Index timeout warning messages](https://github.com/etcd-io/etcd/pull/9897).
-- Adjust [election timeout on server restart](https://github.com/etcd-io/etcd/pull/9415) to reduce [disruptive rejoining servers](https://github.com/etcd-io/etcd/issues/9333).
-  - Previously, etcd fast-forwards election ticks on server start, with only one tick left for leader election. This is to speed up start phase, without having to wait until all election ticks elapse. Advancing election ticks is useful for cross datacenter deployments with larger election timeouts. However, it was affecting cluster availability if the last tick elapses before leader contacts the restarted node.
-  - Now, when etcd restarts, it adjusts election ticks with more than one tick left, thus more time for leader to prevent disruptive restart.
-- Add [Raft Pre-Vote feature](https://github.com/etcd-io/etcd/pull/9352) to reduce [disruptive rejoining servers](https://github.com/etcd-io/etcd/issues/9333).
-  - For instance, a flaky(or rejoining) member may drop in and out, and start campaign. This member will end up with a higher term, and ignore all incoming messages with lower term. In this case, a new leader eventually need to get elected, thus disruptive to cluster availability. Raft implements Pre-Vote phase to prevent this kind of disruptions. If enabled, Raft runs an additional phase of election to check if pre-candidate can get enough votes to win an election.
-- Adjust [periodic compaction retention window](https://github.com/etcd-io/etcd/pull/9485).
-  - e.g. `etcd --auto-compaction-mode=revision --auto-compaction-retention=1000` automatically `Compact` on `"latest revision" - 1000` every 5-minute (when latest revision is 30000, compact on revision 29000).
-  - e.g. Previously, `etcd --auto-compaction-mode=periodic --auto-compaction-retention=24h` automatically `Compact` with 24-hour retention windown for every 2.4-hour. Now, `Compact` happens for every 1-hour.
-  - e.g. Previously, `etcd --auto-compaction-mode=periodic --auto-compaction-retention=30m` automatically `Compact` with 30-minute retention windown for every 3-minute. Now, `Compact` happens for every 30-minute.
-  - Periodic compactor keeps recording latest revisions for every compaction period when given period is less than 1-hour, or for every 1-hour when given compaction period is greater than 1-hour (e.g. 1-hour when `etcd --auto-compaction-mode=periodic --auto-compaction-retention=24h`).
-  - For every compaction period or 1-hour, compactor uses the last revision that was fetched before compaction period, to discard historical data.
-  - The retention window of compaction period moves for every given compaction period or hour.
-  - For instance, when hourly writes are 100 and `etcd --auto-compaction-mode=periodic --auto-compaction-retention=24h`, `v3.2.x`, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 2400, 2640, and 2880 for every 2.4-hour, while `v3.3.3` *or later* compacts revision 2400, 2500, 2600 for every 1-hour.
-  - Futhermore, when `etcd --auto-compaction-mode=periodic --auto-compaction-retention=30m` and writes per minute are about 1000, `v3.3.0`, `v3.3.1`, and `v3.3.2` compact revision 30000, 33000, and 36000, for every 3-minute, while `v3.3.3` *or later* compacts revision 30000, 60000, and 90000, for every 30-minute.
-- Improve [lease expire/revoke operation performance](https://github.com/etcd-io/etcd/pull/9418), address [lease scalability issue](https://github.com/etcd-io/etcd/issues/9496).
-- Make [Lease `Lookup` non-blocking with concurrent `Grant`/`Revoke`](https://github.com/etcd-io/etcd/pull/9229).
-- Make etcd server return `raft.ErrProposalDropped` on internal Raft proposal drop in [v3 applier](https://github.com/etcd-io/etcd/pull/9549) and [v2 applier](https://github.com/etcd-io/etcd/pull/9558).
-  - e.g. a node is removed from cluster, or [`raftpb.MsgProp` arrives at current leader while there is an ongoing leadership transfer](https://github.com/etcd-io/etcd/issues/8975).
-- Add [`snapshot`](https://github.com/etcd-io/etcd/pull/9118) package for easier snapshot workflow (see [`godoc.org/github.com/etcd/clientv3/snapshot`](https://godoc.org/github.com/etcd-io/etcd/clientv3/snapshot) for more).
-- Improve [functional tester](https://github.com/etcd-io/etcd/tree/master/functional) coverage: [proxy layer to run network fault tests in CI](https://github.com/etcd-io/etcd/pull/9081), [TLS is enabled both for server and client](https://github.com/etcd-io/etcd/pull/9534), [liveness mode](https://github.com/etcd-io/etcd/issues/9230), [shuffle test sequence](https://github.com/etcd-io/etcd/issues/9381), [membership reconfiguration failure cases](https://github.com/etcd-io/etcd/pull/9564), [disastrous quorum loss and snapshot recover from a seed member](https://github.com/etcd-io/etcd/pull/9565), [embedded etcd](https://github.com/etcd-io/etcd/pull/9572).
-- Improve [index compaction blocking](https://github.com/etcd-io/etcd/pull/9511) by using a copy on write clone to avoid holding the lock for the traversal of the entire index.
-- Update [JWT methods](https://github.com/etcd-io/etcd/pull/9883) to allow for use of any supported signature method/algorithm.
-- Add [Lease checkpointing](https://github.com/etcd-io/etcd/pull/9924) to persist remaining TTLs to the consensus log periodically so that long lived leases progress toward expiry in the presence of leader elections and server restarts.
-  - Enabled by experimental flag "--experimental-enable-lease-checkpoint".
-- Add [gRPC interceptor for debugging logs](https://github.com/etcd-io/etcd/pull/9990); enable `etcd --debug` flag to see per-request debug information.
-- Add [consistency check in snapshot status](https://github.com/etcd-io/etcd/pull/10109). If consistency check on snapshot file fails, `snapshot status` returns `"snapshot file integrity check failed..."` error.
-- Add [`Verify` function to perform corruption check on WAL contents](https://github.com/etcd-io/etcd/pull/10603).
-- Improve [heartbeat send failure logging](https://github.com/etcd-io/etcd/pull/10663).
-- Support [users with no password](https://github.com/etcd-io/etcd/pull/9817) for reducing security risk introduced by leaked password. The users can only be authenticated with CommonName based auth.
-- Add flag `--experimental-peer-skip-client-san-verification` to [skip verification of peer client address](https://github.com/etcd-io/etcd/pull/10524)
-
-### Breaking Changes
-
-- Require [*Go 1.12+*](https://github.com/etcd-io/etcd/pull/10045).
-- Use [Go module](https://github.com/etcd-io/etcd/pull/10063) for dependency management.
-- Move [`"github.com/coreos/etcd"`](https://github.com/etcd-io/etcd/issues/9965) to [`"github.com/etcd-io/etcd"`](https://github.com/etcd-io/etcd/issues/9965).
-  - Change import path to `"go.etcd.io/etcd"`.
-  - e.g. `import "go.etcd.io/etcd/raft"`.
-- Make [`ETCDCTL_API=3 etcdctl` default](https://github.com/etcd-io/etcd/issues/9600).
-  - Now, `etcdctl set foo bar` must be `ETCDCTL_API=2 etcdctl set foo bar`.
-  - Now, `ETCDCTL_API=3 etcdctl put foo bar` could be just `etcdctl put foo bar`.
-- **Remove `etcd --ca-file` flag**, instead [use `etcd --trusted-ca-file`](https://github.com/etcd-io/etcd/pull/9470) (`etcd --ca-file` flag has been marked deprecated since v2.1).
-- **Remove `etcd --peer-ca-file` flag**, instead [use `etcd --peer-trusted-ca-file`](https://github.com/etcd-io/etcd/pull/9470) (`etcd --peer-ca-file` flag has been marked deprecated since v2.1).
-- **Remove `pkg/transport.TLSInfo.CAFile` field**, instead [use `pkg/transport.TLSInfo.TrustedCAFile`](https://github.com/etcd-io/etcd/pull/9470) (`CAFile` field has been marked deprecated since v2.1).
-- Deprecated `latest` [release container](https://console.cloud.google.com/gcr/images/etcd-development/GLOBAL/etcd) tag.
-  - **`docker pull gcr.io/etcd-development/etcd:latest` would not be up-to-date**.
-- Deprecated [minor](https://semver.org/) version [release container](https://console.cloud.google.com/gcr/images/etcd-development/GLOBAL/etcd) tags.
-  - `docker pull gcr.io/etcd-development/etcd:v3.3` would still work.
-  - **`docker pull gcr.io/etcd-development/etcd:v3.4` would not work**.
-  - Use **`docker pull gcr.io/etcd-development/etcd:v3.4.x`** instead, with the exact patch version.
-- Drop [ACIs from official release](https://github.com/etcd-io/etcd/pull/9059).
-  - [AppC was officially suspended](https://github.com/appc/spec#-disclaimer-), as of late 2016.
-  - [`acbuild`](https://github.com/containers/build#this-project-is-currently-unmaintained) is not maintained anymore.
-  - `*.aci` files are not available from `v3.4` release.
-- Exit on [empty hosts in advertise URLs](https://github.com/etcd-io/etcd/pull/8786).
-  - Address [advertise client URLs accepts empty hosts](https://github.com/etcd-io/etcd/issues/8379).
-  - e.g. exit with error on `--advertise-client-urls=http://:2379`.
-  - e.g. exit with error on `--initial-advertise-peer-urls=http://:2380`.
-- Exit on [shadowed environment variables](https://github.com/etcd-io/etcd/pull/9382).
-  - Address [error on shadowed environment variables](https://github.com/etcd-io/etcd/issues/8380).
-  - e.g. exit with error on `ETCD_NAME=abc etcd --name=def`.
-  - e.g. exit with error on `ETCD_INITIAL_CLUSTER_TOKEN=abc etcd --initial-cluster-token=def`.
-  - e.g. exit with error on `ETCDCTL_ENDPOINTS=abc.com ETCDCTL_API=3 etcdctl endpoint health --endpoints=def.com`.
-- Change [`etcdserverpb.AuthRoleRevokePermissionRequest/key,range_end` fields type from `string` to `bytes`](https://github.com/etcd-io/etcd/pull/9433).
-- Deprecating `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819) instead.
-- Deprecating `etcd_debugging_mvcc_put_total` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_put_total`](https://github.com/etcd-io/etcd/pull/10962) instead.
-- Deprecating `etcd_debugging_mvcc_delete_total` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_delete_total`](https://github.com/etcd-io/etcd/pull/10962) instead.
-- Deprecating `etcd_debugging_mvcc_range_total` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_range_total`](https://github.com/etcd-io/etcd/pull/10968) instead.
-- Deprecating `etcd_debugging_mvcc_txn_total`Prometheus metric  (to be removed in v3.5). Use [`etcd_mvcc_txn_total`](https://github.com/etcd-io/etcd/pull/10968) instead.
-- Rename `etcdserver.ServerConfig.SnapCount` field to `etcdserver.ServerConfig.SnapshotCount`, to be consistent with the flag name `etcd --snapshot-count`.
-- Rename `embed.Config.SnapCount` field to [`embed.Config.SnapshotCount`](https://github.com/etcd-io/etcd/pull/9745), to be consistent with the flag name `etcd --snapshot-count`.
-- Change [`embed.Config.CorsInfo` in `*cors.CORSInfo` type to `embed.Config.CORS` in `map[string]struct{}` type](https://github.com/etcd-io/etcd/pull/9490).
-- Remove [`embed.Config.SetupLogging`](https://github.com/etcd-io/etcd/pull/9572).
-  - Now logger is set up automatically based on [`embed.Config.Logger`, `embed.Config.LogOutputs`, `embed.Config.Debug` fields](https://github.com/etcd-io/etcd/pull/9572).
-- Rename [`etcd --log-output` to `etcd --log-outputs`](https://github.com/etcd-io/etcd/pull/9624) to support multiple log outputs.
-  - **`etcd --log-output`** will be deprecated in v3.5.
-- Rename [**`embed.Config.LogOutput`** to **`embed.Config.LogOutputs`**](https://github.com/etcd-io/etcd/pull/9624) to support multiple log outputs.
-- Change [**`embed.Config.LogOutputs`** type from `string` to `[]string`](https://github.com/etcd-io/etcd/pull/9579) to support multiple log outputs.
-  - Now that `etcd --log-outputs` accepts multiple writers, etcd configuration YAML file `log-outputs` field must be changed to `[]string` type.
-  - Previously, `etcd --config-file etcd.config.yaml` can have `log-outputs: default` field, now must be `log-outputs: [default]`.
-- Deprecating [`etcd --debug`](https://github.com/etcd-io/etcd/pull/10947) flag. Use `etcd --log-level=debug` flag instead.
-  - v3.5 will deprecate `etcd --debug` flag in favor of `etcd --log-level=debug`.
-- Change v3 `etcdctl snapshot` exit codes with [`snapshot` package](https://github.com/etcd-io/etcd/pull/9118/commits/df689f4280e1cce4b9d61300be13ca604d41670a).
-  - Exit on error with exit code 1 (no more exit code 5 or 6 on `snapshot save/restore` commands).
-- Migrate dependency management tool from `glide` to [`golang/dep`](https://github.com/etcd-io/etcd/pull/9155).
-  - <= 3.3 puts `vendor` directory under `cmd/vendor` directory to [prevent conflicting transitive dependencies](https://github.com/etcd-io/etcd/issues/4913).
-  - 3.4 moves `cmd/vendor` directory to `vendor` at repository root.
-  - Remove recursive symlinks in `cmd` directory.
-  - Now `go get/install/build` on `etcd` packages (e.g. `clientv3`, `tools/benchmark`) enforce builds with etcd `vendor` directory.
-- Replace [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway) endpoint `/v3beta` with [`/v3`](https://github.com/etcd-io/etcd/pull/9298).
-  - Deprecated [`/v3alpha`](https://github.com/etcd-io/etcd/pull/9298).
-  - To deprecate [`/v3beta`](https://github.com/etcd-io/etcd/issues/9189) in v3.5.
-  - In v3.4, `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` still works as a fallback to `curl -L http://localhost:2379/v3/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'`, but `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` won't work in v3.5. Use `curl -L http://localhost:2379/v3/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` instead.
-- Change [`wal` package function signatures](https://github.com/etcd-io/etcd/pull/9572) to support [structured logger and logging to file](https://github.com/etcd-io/etcd/issues/9438) in server-side.
-  - Previously, `Open(dirpath string, snap walpb.Snapshot) (*WAL, error)`, now `Open(lg *zap.Logger, dirpath string, snap walpb.Snapshot) (*WAL, error)`.
-  - Previously, `OpenForRead(dirpath string, snap walpb.Snapshot) (*WAL, error)`, now `OpenForRead(lg *zap.Logger, dirpath string, snap walpb.Snapshot) (*WAL, error)`.
-  - Previously, `Repair(dirpath string) bool`, now `Repair(lg *zap.Logger, dirpath string) bool`.
-  - Previously, `Create(dirpath string, metadata []byte) (*WAL, error)`, now `Create(lg *zap.Logger, dirpath string, metadata []byte) (*WAL, error)`.
-- Remove [`pkg/cors` package](https://github.com/etcd-io/etcd/pull/9490).
-- Move internal packages to `etcdserver`.
-  - `"github.com/coreos/etcd/alarm"` to `"go.etcd.io/etcd/etcdserver/api/v3alarm"`.
-  - `"github.com/coreos/etcd/compactor"` to `"go.etcd.io/etcd/etcdserver/api/v3compactor"`.
-  - `"github.com/coreos/etcd/discovery"` to `"go.etcd.io/etcd/etcdserver/api/v2discovery"`.
-  - `"github.com/coreos/etcd/etcdserver/auth"` to `"go.etcd.io/etcd/etcdserver/api/v2auth"`.
-  - `"github.com/coreos/etcd/etcdserver/membership"` to `"go.etcd.io/etcd/etcdserver/api/membership"`.
-  - `"github.com/coreos/etcd/etcdserver/stats"` to `"go.etcd.io/etcd/etcdserver/api/v2stats"`.
-  - `"github.com/coreos/etcd/error"` to `"go.etcd.io/etcd/etcdserver/api/v2error"`.
-  - `"github.com/coreos/etcd/rafthttp"` to `"go.etcd.io/etcd/etcdserver/api/rafthttp"`.
-  - `"github.com/coreos/etcd/snap"` to `"go.etcd.io/etcd/etcdserver/api/snap"`.
-  - `"github.com/coreos/etcd/store"` to `"go.etcd.io/etcd/etcdserver/api/v2store"`.
-- Change [snapshot file permissions](https://github.com/etcd-io/etcd/pull/9977): On Linux, the snapshot file changes from readable by all (mode 0644) to readable by the user only (mode 0600).
-- Change [`pkg/adt.IntervalTree` from `struct` to `interface`](https://github.com/etcd-io/etcd/pull/10959).
-  - See [`pkg/adt` README](https://github.com/etcd-io/etcd/tree/master/pkg/adt) and [`pkg/adt` godoc](https://godoc.org/go.etcd.io/etcd/pkg/adt).
-- Release branch `/version` defines version `3.4.x-pre`, instead of `3.4.y+git`.
-  - Use `3.4.5-pre`, instead of `3.4.4+git`.
-
-### Dependency
-
-- Upgrade [`github.com/coreos/bbolt`](https://github.com/etcd-io/bbolt/releases) from [**`v1.3.1-coreos.6`**](https://github.com/etcd-io/bbolt/releases/tag/v1.3.1-coreos.6) to [`go.etcd.io/bbolt`](https://github.com/etcd-io/bbolt/releases) [**`v1.3.3`**](https://github.com/etcd-io/bbolt/releases/tag/v1.3.3).
-- Upgrade [`google.golang.org/grpc`](https://github.com/grpc/grpc-go/releases) from [**`v1.7.5`**](https://github.com/grpc/grpc-go/releases/tag/v1.7.5) to [**`v1.23.0`**](https://github.com/grpc/grpc-go/releases/tag/v1.23.0).
-- Migrate [`github.com/ugorji/go/codec`](https://github.com/ugorji/go/releases) to [**`github.com/json-iterator/go`**](https://github.com/json-iterator/go), to [regenerate v2 `client`](https://github.com/etcd-io/etcd/pull/9494) (See [#10667](https://github.com/etcd-io/etcd/pull/10667) for more).
-- Migrate [`github.com/ghodss/yaml`](https://github.com/ghodss/yaml/releases) to [**`sigs.k8s.io/yaml`**](https://github.com/kubernetes-sigs/yaml) (See [#10687](https://github.com/etcd-io/etcd/pull/10687) for more).
-- Upgrade [`golang.org/x/crypto`](https://github.com/golang/crypto) from [**`crypto@9419663f5`**](https://github.com/golang/crypto/commit/9419663f5a44be8b34ca85f08abc5fe1be11f8a3) to [**`crypto@0709b304e793`**](https://github.com/golang/crypto/commit/0709b304e793a5edb4a2c0145f281ecdc20838a4).
-- Upgrade [`golang.org/x/net`](https://github.com/golang/net) from [**`net@66aacef3d`**](https://github.com/golang/net/commit/66aacef3dd8a676686c7ae3716979581e8b03c47) to [**`net@adae6a3d119a`**](https://github.com/golang/net/commit/adae6a3d119ae4890b46832a2e88a95adc62b8e7).
-- Upgrade [`golang.org/x/sys`](https://github.com/golang/sys) from [**`sys@ebfc5b463`**](https://github.com/golang/sys/commit/ebfc5b4631820b793c9010c87fd8fef0f39eb082) to [**`sys@56ede360e`**](https://github.com/golang/sys/commit/56ede360ec1c541828fb88741b3f1049406d28f5).
-- Upgrade [`golang.org/x/text`](https://github.com/golang/text) from [**`text@b19bf474d`**](https://github.com/golang/text/commit/b19bf474d317b857955b12035d2c5acb57ce8b01) to [**`v0.3.0`**](https://github.com/golang/text/releases/tag/v0.3.0).
-- Upgrade [`golang.org/x/time`](https://github.com/golang/time) from [**`time@c06e80d93`**](https://github.com/golang/time/commit/c06e80d9300e4443158a03817b8a8cb37d230320) to [**`time@fbb02b229`**](https://github.com/golang/time/commit/fbb02b2291d28baffd63558aa44b4b56f178d650).
-- Upgrade [`github.com/golang/protobuf`](https://github.com/golang/protobuf/releases) from [**`golang/protobuf@1e59b77b5`**](https://github.com/golang/protobuf/commit/1e59b77b52bf8e4b449a57e6f79f21226d571845) to [**`v1.3.2`**](https://github.com/golang/protobuf/releases/tag/v1.3.2).
-- Upgrade [`gopkg.in/yaml.v2`](https://github.com/go-yaml/yaml/releases) from [**`yaml@cd8b52f82`**](https://github.com/go-yaml/yaml/commit/cd8b52f8269e0feb286dfeef29f8fe4d5b397e0b) to [**`yaml@5420a8b67`**](https://github.com/go-yaml/yaml/commit/5420a8b6744d3b0345ab293f6fcba19c978f1183).
-- Upgrade [`github.com/dgrijalva/jwt-go`](https://github.com/dgrijalva/jwt-go/releases) from [**`v3.0.0`**](https://github.com/dgrijalva/jwt-go/releases/tag/v3.0.0) to [**`v3.2.0`**](https://github.com/dgrijalva/jwt-go/releases/tag/v3.2.0).
-- Upgrade [`github.com/soheilhy/cmux`](https://github.com/soheilhy/cmux/releases) from [**`v0.1.3`**](https://github.com/soheilhy/cmux/releases/tag/v0.1.3) to [**`v0.1.4`**](https://github.com/soheilhy/cmux/releases/tag/v0.1.4).
-- Upgrade [`github.com/google/btree`](https://github.com/google/btree/releases) from [**`google/btree@925471ac9`**](https://github.com/google/btree/commit/925471ac9e2131377a91e1595defec898166fe49) to [**`v1.0.0`**](https://github.com/google/btree/releases/tag/v1.0.0).
-- Upgrade [`github.com/spf13/cobra`](https://github.com/spf13/cobra/releases) from [**`spf13/cobra@1c44ec8d3`**](https://github.com/spf13/cobra/commit/1c44ec8d3f1552cac48999f9306da23c4d8a288b) to [**`v0.0.3`**](https://github.com/spf13/cobra/releases/tag/v0.0.3).
-- Upgrade [`github.com/spf13/pflag`](https://github.com/spf13/pflag/releases) from [**`v1.0.0`**](https://github.com/spf13/pflag/releases/tag/v1.0.0) to [**`spf13/pflag@1ce0cc6db`**](https://github.com/spf13/pflag/commit/1ce0cc6db4029d97571db82f85092fccedb572ce).
-- Upgrade [`github.com/coreos/go-systemd`](https://github.com/coreos/go-systemd/releases) from [**`v15`**](https://github.com/coreos/go-systemd/releases/tag/v15) to [**`v17`**](https://github.com/coreos/go-systemd/releases/tag/v17).
-- Upgrade [`github.com/prometheus/client_golang`](https://github.com/prometheus/client_golang/releases) from [**``prometheus/client_golang@5cec1d042``**](https://github.com/prometheus/client_golang/commit/5cec1d0429b02e4323e042eb04dafdb079ddf568) to [**`v1.0.0`**](https://github.com/prometheus/client_golang/releases/tag/v1.0.0).
-- Upgrade [`github.com/grpc-ecosystem/go-grpc-prometheus`](https://github.com/grpc-ecosystem/go-grpc-prometheus/releases) from [**``grpc-ecosystem/go-grpc-prometheus@0dafe0d49``**](https://github.com/grpc-ecosystem/go-grpc-prometheus/commit/0dafe0d496ea71181bf2dd039e7e3f44b6bd11a7) to [**`v1.2.0`**](https://github.com/grpc-ecosystem/go-grpc-prometheus/releases/tag/v1.2.0).
-- Upgrade [`github.com/grpc-ecosystem/grpc-gateway`](https://github.com/grpc-ecosystem/grpc-gateway/releases) from [**`v1.3.1`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.3.1) to [**`v1.4.1`**](https://github.com/grpc-ecosystem/grpc-gateway/releases/tag/v1.4.1).
-- Migrate [`github.com/kr/pty`](https://github.com/kr/pty/releases) to [**`github.com/creack/pty`**](https://github.com/creack/pty/releases/tag/v1.1.7), as the later has replaced the original module.
-- Upgrade [`github.com/gogo/protobuf`](https://github.com/gogo/protobuf/releases) from [**`v1.0.0`**](https://github.com/gogo/protobuf/releases/tag/v1.0.0) to [**`v1.2.1`**](https://github.com/gogo/protobuf/releases/tag/v1.2.1).
-
-### Metrics, Monitoring
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Add [`etcd_snap_db_fsync_duration_seconds_count`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_snap_db_save_total_duration_seconds_bucket`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_send_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_success`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_failures`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_snapshot_receive_total_duration_seconds`](https://github.com/etcd-io/etcd/pull/9997) Prometheus metric.
-- Add [`etcd_network_active_peers`](https://github.com/etcd-io/etcd/pull/9762) Prometheus metric.
-  - Let's say `"7339c4e5e833c029"` server `/metrics` returns `etcd_network_active_peers{Local="7339c4e5e833c029",Remote="729934363faa4a24"} 1` and `etcd_network_active_peers{Local="7339c4e5e833c029",Remote="b548c2511513015"} 1`. This indicates that the local node `"7339c4e5e833c029"` currently has two active remote peers `"729934363faa4a24"` and `"b548c2511513015"` in a 3-node cluster. If the node `"b548c2511513015"` is down, the local node `"7339c4e5e833c029"` will show `etcd_network_active_peers{Local="7339c4e5e833c029",Remote="729934363faa4a24"} 1` and `etcd_network_active_peers{Local="7339c4e5e833c029",Remote="b548c2511513015"} 0`.
-- Add [`etcd_network_disconnected_peers_total`](https://github.com/etcd-io/etcd/pull/9762) Prometheus metric.
-  - If a remote peer `"b548c2511513015"` is down, the local node `"7339c4e5e833c029"` server `/metrics` would return `etcd_network_disconnected_peers_total{Local="7339c4e5e833c029",Remote="b548c2511513015"} 1`, while active peer metrics will show `etcd_network_active_peers{Local="7339c4e5e833c029",Remote="729934363faa4a24"} 1` and `etcd_network_active_peers{Local="7339c4e5e833c029",Remote="b548c2511513015"} 0`.
-- Add [`etcd_network_server_stream_failures_total`](https://github.com/etcd-io/etcd/pull/9760) Prometheus metric.
-  - e.g. `etcd_network_server_stream_failures_total{API="lease-keepalive",Type="receive"} 1`
-  - e.g. `etcd_network_server_stream_failures_total{API="watch",Type="receive"} 1`
-- Improve [`etcd_network_peer_round_trip_time_seconds`](https://github.com/etcd-io/etcd/pull/10155) Prometheus metric to track leader heartbeats.
-  - Previously, it only samples the TCP connection for snapshot messages.
-- Increase [`etcd_network_peer_round_trip_time_seconds`](https://github.com/etcd-io/etcd/pull/9762) Prometheus metric histogram upper-bound.
-  - Previously, highest bucket only collects requests taking 0.8192 seconds or more.
-  - Now, highest buckets collect 0.8192 seconds, 1.6384 seconds, and 3.2768 seconds or more.
-- Add [`etcd_server_is_leader`](https://github.com/etcd-io/etcd/pull/9587) Prometheus metric.
-- Add [`etcd_server_id`](https://github.com/etcd-io/etcd/pull/9998) Prometheus metric.
-- Add [`etcd_cluster_version`](https://github.com/etcd-io/etcd/pull/10257) Prometheus metric.
-- Add [`etcd_server_version`](https://github.com/etcd-io/etcd/pull/8960) Prometheus metric.
-  - To replace [Kubernetes `etcd-version-monitor`](https://github.com/etcd-io/etcd/issues/8948).
-- Add [`etcd_server_go_version`](https://github.com/etcd-io/etcd/pull/9957) Prometheus metric.
-- Add [`etcd_server_health_success`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_health_failures`](https://github.com/etcd-io/etcd/pull/10156) Prometheus metric.
-- Add [`etcd_server_read_indexes_failed_total`](https://github.com/etcd-io/etcd/pull/10094) Prometheus metric.
-- Add [`etcd_server_heartbeat_send_failures_total`](https://github.com/etcd-io/etcd/pull/9761) Prometheus metric.
-- Add [`etcd_server_slow_apply_total`](https://github.com/etcd-io/etcd/pull/9761) Prometheus metric.
-- Add [`etcd_server_slow_read_indexes_total`](https://github.com/etcd-io/etcd/pull/9897) Prometheus metric.
-- Add [`etcd_server_quota_backend_bytes`](https://github.com/etcd-io/etcd/pull/9820) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-- Add [`etcd_mvcc_db_total_size_in_use_in_bytes`](https://github.com/etcd-io/etcd/pull/9256) Prometheus metric.
-  - Use it with `etcd_mvcc_db_total_size_in_bytes` and `etcd_mvcc_db_total_size_in_use_in_bytes`.
-  - `etcd_server_quota_backend_bytes 2.147483648e+09` means current quota size is 2 GB.
-  - `etcd_mvcc_db_total_size_in_bytes 20480` means current physically allocated DB size is 20 KB.
-  - `etcd_mvcc_db_total_size_in_use_in_bytes 16384` means future DB size if defragment operation is complete.
-  - `etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes` is the number of bytes that can be saved on disk with defragment operation.
-- Add [`etcd_snap_fsync_duration_seconds`](https://github.com/etcd-io/etcd/pull/9762) Prometheus metric.
-- Add [`etcd_disk_backend_defrag_duration_seconds`](https://github.com/etcd-io/etcd/pull/9761) Prometheus metric.
-- Add [`etcd_mvcc_hash_duration_seconds`](https://github.com/etcd-io/etcd/pull/9761) Prometheus metric.
-- Add [`etcd_mvcc_hash_rev_duration_seconds`](https://github.com/etcd-io/etcd/pull/9761) Prometheus metric.
-- Add [`etcd_debugging_disk_backend_commit_rebalance_duration_seconds`](https://github.com/etcd-io/etcd/pull/9834) Prometheus metric.
-- Add [`etcd_debugging_disk_backend_commit_spill_duration_seconds`](https://github.com/etcd-io/etcd/pull/9834) Prometheus metric.
-- Add [`etcd_debugging_disk_backend_commit_write_duration_seconds`](https://github.com/etcd-io/etcd/pull/9834) Prometheus metric.
-- Add [`etcd_debugging_lease_granted_total`](https://github.com/etcd-io/etcd/pull/9778) Prometheus metric.
-- Add [`etcd_debugging_lease_revoked_total`](https://github.com/etcd-io/etcd/pull/9778) Prometheus metric.
-- Add [`etcd_debugging_lease_renewed_total`](https://github.com/etcd-io/etcd/pull/9778) Prometheus metric.
-- Add [`etcd_debugging_lease_ttl_total`](https://github.com/etcd-io/etcd/pull/9778) Prometheus metric.
-- Add [`etcd_server_is_learner`](https://github.com/etcd-io/etcd/pull/10731) Prometheus metric.
-- Add [`etcd_server_learner_promote_failures`](https://github.com/etcd-io/etcd/pull/10731) Prometheus metric.
-- Add [`etcd_server_learner_promote_successes`](https://github.com/etcd-io/etcd/pull/10731) Prometheus metric.
-- Increase [`etcd_debugging_mvcc_index_compaction_pause_duration_milliseconds`](https://github.com/etcd-io/etcd/pull/9762) Prometheus metric histogram upper-bound.
-  - Previously, highest bucket only collects requests taking 1.024 seconds or more.
-  - Now, highest buckets collect 1.024 seconds, 2.048 seconds, and 4.096 seconds or more.
-- Fix missing [`etcd_network_peer_sent_failures_total`](https://github.com/etcd-io/etcd/pull/9437) Prometheus metric count.
-- Fix [`etcd_debugging_server_lease_expired_total`](https://github.com/etcd-io/etcd/pull/9557) Prometheus metric.
-- Fix [race conditions in v2 server stat collecting](https://github.com/etcd-io/etcd/pull/9562).
-- Change [gRPC proxy to expose etcd server endpoint /metrics](https://github.com/etcd-io/etcd/pull/10618).
-  - The metrics that were exposed via the proxy were not etcd server members but instead the proxy itself.
-- Fix bug where [db_compaction_total_duration_milliseconds metric incorrectly measured duration as 0](https://github.com/etcd-io/etcd/pull/10646).
-- Deprecating `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_db_total_size_in_bytes`](https://github.com/etcd-io/etcd/pull/9819) instead.
-- Deprecating `etcd_debugging_mvcc_put_total` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_put_total`](https://github.com/etcd-io/etcd/pull/10962) instead.
-- Deprecating `etcd_debugging_mvcc_delete_total` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_delete_total`](https://github.com/etcd-io/etcd/pull/10962) instead.
-- Deprecating `etcd_debugging_mvcc_range_total` Prometheus metric (to be removed in v3.5). Use [`etcd_mvcc_range_total`](https://github.com/etcd-io/etcd/pull/10968) instead.
-- Deprecating `etcd_debugging_mvcc_txn_total`Prometheus metric  (to be removed in v3.5). Use [`etcd_mvcc_txn_total`](https://github.com/etcd-io/etcd/pull/10968) instead.
-
-### Security, Authentication
-
-See [security doc](https://github.com/etcd-io/etcd/blob/master/Documentation/op-guide/security.md) for more details.
-
-- Support TLS cipher suite whitelisting.
-  - To block [weak cipher suites](https://github.com/etcd-io/etcd/issues/8320).
-  - TLS handshake fails when client hello is requested with invalid cipher suites.
-  - Add [`etcd --cipher-suites`](https://github.com/etcd-io/etcd/pull/9801) flag.
-  - If empty, Go auto-populates the list.
-- Add [`etcd --host-whitelist`](https://github.com/etcd-io/etcd/pull/9372) flag, [`etcdserver.Config.HostWhitelist`](https://github.com/etcd-io/etcd/pull/9372), and [`embed.Config.HostWhitelist`](https://github.com/etcd-io/etcd/pull/9372), to prevent ["DNS Rebinding"](https://en.wikipedia.org/wiki/DNS_rebinding) attack.
-  - Any website can simply create an authorized DNS name, and direct DNS to `"localhost"` (or any other address). Then, all HTTP endpoints of etcd server listening on `"localhost"` becomes accessible, thus vulnerable to [DNS rebinding attacks (CVE-2018-5702)](https://bugs.chromium.org/p/project-zero/issues/detail?id=1447#c2).
-  - Client origin enforce policy works as follow:
-    - If client connection is secure via HTTPS, allow any hostnames..
-    - If client connection is not secure and `"HostWhitelist"` is not empty, only allow HTTP requests whose Host field is listed in whitelist.
-  - By default, `"HostWhitelist"` is `"*"`, which means insecure server allows all client HTTP requests.
-  - Note that the client origin policy is enforced whether authentication is enabled or not, for tighter controls.
-  - When specifying hostnames, loopback addresses are not added automatically. To allow loopback interfaces, add them to whitelist manually (e.g. `"localhost"`, `"127.0.0.1"`, etc.).
-  - e.g. `etcd --host-whitelist example.com`, then the server will reject all HTTP requests whose Host field is not `example.com` (also rejects requests to `"localhost"`).
-- Support [`etcd --cors`](https://github.com/etcd-io/etcd/pull/9490) in v3 HTTP requests (gRPC gateway).
-- Support [`ttl` field for `etcd` Authentication JWT token](https://github.com/etcd-io/etcd/pull/8302).
-  - e.g. `etcd --auth-token jwt,pub-key=<pub key path>,priv-key=<priv key path>,sign-method=<sign method>,ttl=5m`.
-- Allow empty token provider in [`etcdserver.ServerConfig.AuthToken`](https://github.com/etcd-io/etcd/pull/9369).
-- Fix [TLS reload](https://github.com/etcd-io/etcd/pull/9570) when [certificate SAN field only includes IP addresses but no domain names](https://github.com/etcd-io/etcd/issues/9541).
-  - In Go, server calls `(*tls.Config).GetCertificate` for TLS reload if and only if server's `(*tls.Config).Certificates` field is not empty, or `(*tls.ClientHelloInfo).ServerName` is not empty with a valid SNI from the client. Previously, etcd always populates `(*tls.Config).Certificates` on the initial client TLS handshake, as non-empty. Thus, client was always expected to supply a matching SNI in order to pass the TLS verification and to trigger `(*tls.Config).GetCertificate` to reload TLS assets.
-  - However, a certificate whose SAN field does [not include any domain names but only IP addresses](https://github.com/etcd-io/etcd/issues/9541) would request `*tls.ClientHelloInfo` with an empty `ServerName` field, thus failing to trigger the TLS reload on initial TLS handshake; this becomes a problem when expired certificates need to be replaced online.
-  - Now, `(*tls.Config).Certificates` is created empty on initial TLS client handshake, first to trigger `(*tls.Config).GetCertificate`, and then to populate rest of the certificates on every new TLS connection, even when client SNI is empty (e.g. cert only includes IPs).
-
-### etcd server
-
-- Add [`rpctypes.ErrLeaderChanged`](https://github.com/etcd-io/etcd/pull/10094).
-  - Now linearizable requests with read index would fail fast when there is a leadership change, instead of waiting until context timeout.
-- Add [`etcd --initial-election-tick-advance`](https://github.com/etcd-io/etcd/pull/9591) flag to configure initial election tick fast-forward.
-  - By default, `etcd --initial-election-tick-advance=true`, then local member fast-forwards election ticks to speed up "initial" leader election trigger.
-  - This benefits the case of larger election ticks. For instance, cross datacenter deployment may require longer election timeout of 10-second. If true, local node does not need wait up to 10-second. Instead, forwards its election ticks to 8-second, and have only 2-second left before leader election.
-  - Major assumptions are that: cluster has no active leader thus advancing ticks enables faster leader election. Or cluster already has an established leader, and rejoining follower is likely to receive heartbeats from the leader after tick advance and before election timeout.
-  - However, when network from leader to rejoining follower is congested, and the follower does not receive leader heartbeat within left election ticks, disruptive election has to happen thus affecting cluster availabilities.
-  - Now, this can be disabled by setting `etcd --initial-election-tick-advance=false`.
-  - Disabling this would slow down initial bootstrap process for cross datacenter deployments. Make tradeoffs by configuring `etcd --initial-election-tick-advance` at the cost of slow initial bootstrap.
-  - If single-node, it advances ticks regardless.
-  - Address [disruptive rejoining follower node](https://github.com/etcd-io/etcd/issues/9333).
-- Add [`etcd --pre-vote`](https://github.com/etcd-io/etcd/pull/9352) flag to enable to run an additional Raft election phase.
-  - For instance, a flaky(or rejoining) member may drop in and out, and start campaign. This member will end up with a higher term, and ignore all incoming messages with lower term. In this case, a new leader eventually need to get elected, thus disruptive to cluster availability. Raft implements Pre-Vote phase to prevent this kind of disruptions. If enabled, Raft runs an additional phase of election to check if pre-candidate can get enough votes to win an election.
-  - `etcd --pre-vote=false` by default.
-  - v3.5 will enable `etcd --pre-vote=true` by default.
-- Add [`etcd --discovery-srv-name`](https://github.com/etcd-io/etcd/pull/8690) flag to support custom DNS SRV name with discovery.
-  - If not given, etcd queries `_etcd-server-ssl._tcp.[YOUR_HOST]` and `_etcd-server._tcp.[YOUR_HOST]`.
-  - If `etcd --discovery-srv-name="foo"`, then query `_etcd-server-ssl-foo._tcp.[YOUR_HOST]` and `_etcd-server-foo._tcp.[YOUR_HOST]`.
-  - Useful for operating multiple etcd clusters under the same domain.
-- Support TLS cipher suite whitelisting.
-  - To block [weak cipher suites](https://github.com/etcd-io/etcd/issues/8320).
-  - TLS handshake fails when client hello is requested with invalid cipher suites.
-  - Add [`etcd --cipher-suites`](https://github.com/etcd-io/etcd/pull/9801) flag.
-  - If empty, Go auto-populates the list.
-- Support [`etcd --cors`](https://github.com/etcd-io/etcd/pull/9490) in v3 HTTP requests (gRPC gateway).
-- Rename [`etcd --log-output` to `etcd --log-outputs`](https://github.com/etcd-io/etcd/pull/9624) to support multiple log outputs.
-  - **`etcd --log-output` will be deprecated in v3.5**.
-- Add [`etcd --logger`](https://github.com/etcd-io/etcd/pull/9572) flag to support [structured logger and multiple log outputs](https://github.com/etcd-io/etcd/issues/9438) in server-side.
-  - **`etcd --logger=capnslog` will be deprecated in v3.5**.
-  - Main motivation is to promote automated etcd monitoring, rather than looking back server logs when it starts breaking. Future development will make etcd log as few as possible, and make etcd easier to monitor with metrics and alerts.
-  - `etcd --logger=capnslog --log-outputs=default` is the default setting and same as previous etcd server logging format.
-  - `etcd --logger=zap --log-outputs=default` is not supported when `etcd --logger=zap`.
-    - Use `etcd --logger=zap --log-outputs=stderr` instead.
-    - Or, use `etcd --logger=zap --log-outputs=systemd/journal` to send logs to the local systemd journal.
-    - Previously, if etcd parent process ID (PPID) is 1 (e.g. run with systemd), `etcd --logger=capnslog --log-outputs=default` redirects server logs to local systemd journal. And if write to journald fails, it writes to `os.Stderr` as a fallback.
-    - However, even with PPID 1, it can fail to dial systemd journal (e.g. run embedded etcd with Docker container). Then, [every single log write will fail](https://github.com/etcd-io/etcd/pull/9729) and fall back to `os.Stderr`, which is inefficient.
-    - To avoid this problem, systemd journal logging must be configured manually.
-  - `etcd --logger=zap --log-outputs=stderr` will log server operations in [JSON-encoded format](https://godoc.org/go.uber.org/zap#NewProductionEncoderConfig) and writes logs to `os.Stderr`. Use this to override journald log redirects.
-  - `etcd --logger=zap --log-outputs=stdout` will log server operations in [JSON-encoded format](https://godoc.org/go.uber.org/zap#NewProductionEncoderConfig) and writes logs to `os.Stdout` Use this to override journald log redirects.
-  - `etcd --logger=zap --log-outputs=a.log` will log server operations in [JSON-encoded format](https://godoc.org/go.uber.org/zap#NewProductionEncoderConfig) and writes logs to the specified file `a.log`.
-  - `etcd --logger=zap --log-outputs=a.log,b.log,c.log,stdout` [writes server logs to multiple files `a.log`, `b.log` and `c.log` at the same time](https://github.com/etcd-io/etcd/pull/9579) and outputs to `os.Stderr`, in [JSON-encoded format](https://godoc.org/go.uber.org/zap#NewProductionEncoderConfig).
-  - `etcd --logger=zap --log-outputs=/dev/null` will discard all server logs.
-- Add [`etcd --log-level`](https://github.com/etcd-io/etcd/pull/10947) flag to support log level.
-  - v3.5 will deprecate `etcd --debug` flag in favor of `etcd --log-level=debug`.
-- Add [`etcd --backend-batch-limit`](https://github.com/etcd-io/etcd/pull/10283) flag.
-- Add [`etcd --backend-batch-interval`](https://github.com/etcd-io/etcd/pull/10283) flag.
-- Fix [`mvcc` "unsynced" watcher restore operation](https://github.com/etcd-io/etcd/pull/9281).
-  - "unsynced" watcher is watcher that needs to be in sync with events that have happened.
-  - That is, "unsynced" watcher is the slow watcher that was requested on old revision.
-  - "unsynced" watcher restore operation was not correctly populating its underlying watcher group.
-  - Which possibly causes [missing events from "unsynced" watchers](https://github.com/etcd-io/etcd/issues/9086).
-  - A node gets network partitioned with a watcher on a future revision, and falls behind receiving a leader snapshot after partition gets removed. When applying this snapshot, etcd watch storage moves current synced watchers to unsynced since sync watchers might have become stale during network partition. And reset synced watcher group to restart watcher routines. Previously, there was a bug when moving from synced watcher group to unsynced, thus client would miss events when the watcher was requested to the network-partitioned node.
-- Fix [`mvcc` server panic from restore operation](https://github.com/etcd-io/etcd/pull/9775).
-  - Let's assume that a watcher had been requested with a future revision X and sent to node A that became network-partitioned thereafter. Meanwhile, cluster makes progress. Then when the partition gets removed, the leader sends a snapshot to node A. Previously if the snapshot's latest revision is still lower than the watch revision X,  **etcd server panicked** during snapshot restore operation.
-  - Now, this server-side panic has been fixed.
-- Fix [server panic on invalid Election Proclaim/Resign HTTP(S) requests](https://github.com/etcd-io/etcd/pull/9379).
-  - Previously, wrong-formatted HTTP requests to Election API could trigger panic in etcd server.
-  - e.g. `curl -L http://localhost:2379/v3/election/proclaim -X POST -d '{"value":""}'`, `curl -L http://localhost:2379/v3/election/resign -X POST -d '{"value":""}'`.
-- Fix [revision-based compaction retention parsing](https://github.com/etcd-io/etcd/pull/9339).
-  - Previously, `etcd --auto-compaction-mode revision --auto-compaction-retention 1` was [translated to revision retention 3600000000000](https://github.com/etcd-io/etcd/issues/9337).
-  - Now, `etcd --auto-compaction-mode revision --auto-compaction-retention 1` is correctly parsed as revision retention 1.
-- Prevent [overflow by large `TTL` values for `Lease` `Grant`](https://github.com/etcd-io/etcd/pull/9399).
-  - `TTL` parameter to `Grant` request is unit of second.
-  - Leases with too large `TTL` values exceeding `math.MaxInt64` [expire in unexpected ways](https://github.com/etcd-io/etcd/issues/9374).
-  - Server now returns `rpctypes.ErrLeaseTTLTooLarge` to client, when the requested `TTL` is larger than *9,000,000,000 seconds* (which is >285 years).
-  - Again, etcd `Lease` is meant for short-periodic keepalives or sessions, in the range of seconds or minutes. Not for hours or days!
-- Fix [expired lease revoke](https://github.com/etcd-io/etcd/pull/10693).
-  - Fix ["the key is not deleted when the bound lease expires"](https://github.com/etcd-io/etcd/issues/10686).
-- Enable etcd server [`raft.Config.CheckQuorum` when starting with `ForceNewCluster`](https://github.com/etcd-io/etcd/pull/9347).
-- Allow [non-WAL files in `etcd --wal-dir` directory](https://github.com/etcd-io/etcd/pull/9743).
-  - Previously, existing files such as [`lost+found`](https://github.com/etcd-io/etcd/issues/7287) in WAL directory prevent etcd server boot.
-  - Now, WAL directory that contains only `lost+found` or a file that's not suffixed with `.wal` is considered non-initialized.
-- Fix [`ETCD_CONFIG_FILE` env variable parsing in `etcd`](https://github.com/etcd-io/etcd/pull/10762).
-- Fix [race condition in `rafthttp` transport pause/resume](https://github.com/etcd-io/etcd/pull/10826).
-- Fix [server crash from creating an empty role](https://github.com/etcd-io/etcd/pull/10907).
-  - Previously, creating a role with an empty name crashed etcd server with an error code `Unavailable`.
-  - Now, creating a role with an empty name is not allowed with an error code `InvalidArgument`.
-
-### API
-
-- Add `isLearner` field to `etcdserverpb.Member`, `etcdserverpb.MemberAddRequest` and `etcdserverpb.StatusResponse` as part of [raft learner implementation](https://github.com/etcd-io/etcd/pull/10725).
-- Add `MemberPromote` rpc to `etcdserverpb.Cluster` interface and the corresponding `MemberPromoteRequest` and `MemberPromoteResponse` as part of [raft learner implementation](https://github.com/etcd-io/etcd/pull/10725).
-- Add [`snapshot`](https://github.com/etcd-io/etcd/pull/9118) package for snapshot restore/save operations (see [`godoc.org/github.com/etcd/clientv3/snapshot`](https://godoc.org/github.com/coreos/etcd/clientv3/snapshot) for more).
-- Add [`watch_id` field to `etcdserverpb.WatchCreateRequest`](https://github.com/etcd-io/etcd/pull/9065) to allow user-provided watch ID to `mvcc`.
-  - Corresponding `watch_id` is returned via `etcdserverpb.WatchResponse`, if any.
-- Add [`fragment` field to `etcdserverpb.WatchCreateRequest`](https://github.com/etcd-io/etcd/pull/9291) to request etcd server to [split watch events](https://github.com/etcd-io/etcd/issues/9294) when the total size of events exceeds `etcd --max-request-bytes` flag value plus gRPC-overhead 512 bytes.
-  - The default server-side request bytes limit is `embed.DefaultMaxRequestBytes` which is 1.5 MiB plus gRPC-overhead 512 bytes.
-  - If watch response events exceed this server-side request limit and watch request is created with `fragment` field `true`, the server will split watch events into a set of chunks, each of which is a subset of watch events below server-side request limit.
-  - Useful when client-side has limited bandwidths.
-  - For example, watch response contains 10 events, where each event is 1 MiB. And server `etcd --max-request-bytes` flag value is 1 MiB. Then, server will send 10 separate fragmented events to the client.
-  - For example, watch response contains 5 events, where each event is 2 MiB. And server `etcd --max-request-bytes` flag value is 1 MiB and `clientv3.Config.MaxCallRecvMsgSize` is 1 MiB. Then, server will try to send 5 separate fragmented events to the client, and the client will error with `"code = ResourceExhausted desc = grpc: received message larger than max (...)"`.
-  - Client must implement fragmented watch event merge (which `clientv3` does in etcd v3.4).
-- Add [`raftAppliedIndex` field to `etcdserverpb.StatusResponse`](https://github.com/etcd-io/etcd/pull/9176) for current Raft applied index.
-- Add [`errors` field to `etcdserverpb.StatusResponse`](https://github.com/etcd-io/etcd/pull/9206) for server-side error.
-  - e.g. `"etcdserver: no leader", "NOSPACE", "CORRUPT"`
-- Add [`dbSizeInUse` field to `etcdserverpb.StatusResponse`](https://github.com/etcd-io/etcd/pull/9256) for actual DB size after compaction.
-- Add [`WatchRequest.WatchProgressRequest`](https://github.com/etcd-io/etcd/pull/9869).
-  - To manually trigger broadcasting watch progress event (empty watch response with latest header) to all associated watch streams.
-  - Think of it as `WithProgressNotify` that can be triggered manually.
-
-Note: **v3.5 will deprecate `etcd --log-package-levels` flag for `capnslog`**; `etcd --logger=zap --log-outputs=stderr` will the default. **v3.5 will deprecate `[CLIENT-URL]/config/local/log` endpoint.**
-
-### Package `embed`
-
-- Add [`embed.Config.CipherSuites`](https://github.com/etcd-io/etcd/pull/9801) to specify a list of supported cipher suites for TLS handshake between client/server  and peers.
-  - If empty, Go auto-populates the list.
-  - Both `embed.Config.ClientTLSInfo.CipherSuites` and `embed.Config.CipherSuites` cannot be non-empty at the same time.
-  - If not empty, specify either `embed.Config.ClientTLSInfo.CipherSuites` or `embed.Config.CipherSuites`.
-- Add [`embed.Config.InitialElectionTickAdvance`](https://github.com/etcd-io/etcd/pull/9591) to enable/disable initial election tick fast-forward.
-  - `embed.NewConfig()` would return `*embed.Config` with `InitialElectionTickAdvance` as true by default.
-- Define [`embed.CompactorModePeriodic`](https://godoc.org/github.com/etcd-io/etcd/embed#pkg-variables) for `compactor.ModePeriodic`.
-- Define [`embed.CompactorModeRevision`](https://godoc.org/github.com/etcd-io/etcd/embed#pkg-variables) for `compactor.ModeRevision`.
-- Change [`embed.Config.CorsInfo` in `*cors.CORSInfo` type to `embed.Config.CORS` in `map[string]struct{}` type](https://github.com/etcd-io/etcd/pull/9490).
-- Remove [`embed.Config.SetupLogging`](https://github.com/etcd-io/etcd/pull/9572).
-  - Now logger is set up automatically based on [`embed.Config.Logger`, `embed.Config.LogOutputs`, `embed.Config.Debug` fields](https://github.com/etcd-io/etcd/pull/9572).
-- Add [`embed.Config.Logger`](https://github.com/etcd-io/etcd/pull/9518) to support [structured logger `zap`](https://github.com/uber-go/zap) in server-side.
-- Add [`embed.Config.LogLevel`](https://github.com/etcd-io/etcd/pull/10947).
-- Rename `embed.Config.SnapCount` field to [`embed.Config.SnapshotCount`](https://github.com/etcd-io/etcd/pull/9745), to be consistent with the flag name `etcd --snapshot-count`.
-- Rename [**`embed.Config.LogOutput`** to **`embed.Config.LogOutputs`**](https://github.com/etcd-io/etcd/pull/9624) to support multiple log outputs.
-- Change [**`embed.Config.LogOutputs`** type from `string` to `[]string`](https://github.com/etcd-io/etcd/pull/9579) to support multiple log outputs.
-- Add [`embed.Config.BackendBatchLimit`](https://github.com/etcd-io/etcd/pull/10283) field.
-- Add [`embed.Config.BackendBatchInterval`](https://github.com/etcd-io/etcd/pull/10283) field.
-
-### Package `integration`
-
-- Add [`CLUSTER_DEBUG` to enable test cluster logging](https://github.com/etcd-io/etcd/pull/9678).
-  - Deprecated `capnslog` in integration tests.
-
-### client v3
-
-- Add [`MemberAddAsLearner`](https://github.com/etcd-io/etcd/pull/10725) to `Clientv3.Cluster` interface. This API is used to add a learner member to etcd cluster.
-- Add [`MemberPromote`](https://github.com/etcd-io/etcd/pull/10727) to `Clientv3.Cluster` interface. This API is used to promote a learner member in etcd cluster.
-- Client may receive [`rpctypes.ErrLeaderChanged`](https://github.com/etcd-io/etcd/pull/10094) from server.
-  - Now linearizable requests with read index would fail fast when there is a leadership change, instead of waiting until context timeout.
-- Add [`WithFragment` `OpOption`](https://github.com/etcd-io/etcd/pull/9291) to support [watch events fragmentation](https://github.com/etcd-io/etcd/issues/9294) when the total size of events exceeds `etcd --max-request-bytes` flag value plus gRPC-overhead 512 bytes.
-  - Watch fragmentation is disabled by default.
-  - The default server-side request bytes limit is `embed.DefaultMaxRequestBytes` which is 1.5 MiB plus gRPC-overhead 512 bytes.
-  - If watch response events exceed this server-side request limit and watch request is created with `fragment` field `true`, the server will split watch events into a set of chunks, each of which is a subset of watch events below server-side request limit.
-  - Useful when client-side has limited bandwidths.
-  - For example, watch response contains 10 events, where each event is 1 MiB. And server `etcd --max-request-bytes` flag value is 1 MiB. Then, server will send 10 separate fragmented events to the client.
-  - For example, watch response contains 5 events, where each event is 2 MiB. And server `etcd --max-request-bytes` flag value is 1 MiB and `clientv3.Config.MaxCallRecvMsgSize` is 1 MiB. Then, server will try to send 5 separate fragmented events to the client, and the client will error with `"code = ResourceExhausted desc = grpc: received message larger than max (...)"`.
-- Add [`Watcher.RequestProgress` method](https://github.com/etcd-io/etcd/pull/9869).
-  - To manually trigger broadcasting watch progress event (empty watch response with latest header) to all associated watch streams.
-  - Think of it as `WithProgressNotify` that can be triggered manually.
-- Fix [lease keepalive interval updates when response queue is full](https://github.com/etcd-io/etcd/pull/9952).
-  - If `<-chan *clientv3LeaseKeepAliveResponse` from `clientv3.Lease.KeepAlive` was never consumed or channel is full, client was [sending keepalive request every 500ms](https://github.com/etcd-io/etcd/issues/9911) instead of expected rate of every "TTL / 3" duration.
-- Change [snapshot file permissions](https://github.com/etcd-io/etcd/pull/9977): On Linux, the snapshot file changes from readable by all (mode 0644) to readable by the user only (mode 0600).
-- Client may choose to send keepalive pings to server using [`PermitWithoutStream`](https://github.com/etcd-io/etcd/pull/10146).
-  - By setting `PermitWithoutStream` to true, client can send keepalive pings to server without any active streams(RPCs). In other words, it allows sending keepalive pings with unary or simple RPC calls.
-  - `PermitWithoutStream` is set to false by default.
-- Fix logic on [release lock key if cancelled](https://github.com/etcd-io/etcd/pull/10153) in `clientv3/concurrency` package.
-- Fix [`(*Client).Endpoints()` method race condition](https://github.com/etcd-io/etcd/pull/10595).
-
-### etcdctl v3
-
-- Make [`ETCDCTL_API=3 etcdctl` default](https://github.com/etcd-io/etcd/issues/9600).
-  - Now, `etcdctl set foo bar` must be `ETCDCTL_API=2 etcdctl set foo bar`.
-  - Now, `ETCDCTL_API=3 etcdctl put foo bar` could be just `etcdctl put foo bar`.
-- Add [`etcdctl member add --learner` and `etcdctl member promote`](https://github.com/etcd-io/etcd/pull/10725) to add and promote raft learner member in etcd cluster.
-- Add [`etcdctl --password`](https://github.com/etcd-io/etcd/pull/9730) flag.
-  - To support [`:` character in user name](https://github.com/etcd-io/etcd/issues/9691).
-  - e.g. `etcdctl --user user --password password get foo`
-- Add [`etcdctl user add --new-user-password`](https://github.com/etcd-io/etcd/pull/9730) flag.
-- Add [`etcdctl check datascale`](https://github.com/etcd-io/etcd/pull/9185) command.
-- Add [`etcdctl check datascale --auto-compact, --auto-defrag`](https://github.com/etcd-io/etcd/pull/9351) flags.
-- Add [`etcdctl check perf --auto-compact, --auto-defrag`](https://github.com/etcd-io/etcd/pull/9330) flags.
-- Add [`etcdctl defrag --cluster`](https://github.com/etcd-io/etcd/pull/9390) flag.
-- Add ["raft applied index" field to `endpoint status`](https://github.com/etcd-io/etcd/pull/9176).
-- Add ["errors" field to `endpoint status`](https://github.com/etcd-io/etcd/pull/9206).
-- Add [`etcdctl endpoint health --write-out` support](https://github.com/etcd-io/etcd/pull/9540).
-  - Previously, [`etcdctl endpoint health --write-out json` did not work](https://github.com/etcd-io/etcd/issues/9532).
-- Add [missing newline in `etcdctl endpoint health`](https://github.com/etcd-io/etcd/pull/10793).
-- Fix [`etcdctl watch [key] [range_end] -- [exec-command…]`](https://github.com/etcd-io/etcd/pull/9688) parsing.
-  - Previously,  `ETCDCTL_API=3 etcdctl watch foo -- echo watch event received` panicked.
-- Fix [`etcdctl move-leader` command for TLS-enabled endpoints](https://github.com/etcd-io/etcd/pull/9807).
-- Add [`progress` command to `etcdctl watch --interactive`](https://github.com/etcd-io/etcd/pull/9869).
-  - To manually trigger broadcasting watch progress event (empty watch response with latest header) to all associated watch streams.
-  - Think of it as `WithProgressNotify` that can be triggered manually.
-- Add [timeout](https://github.com/etcd-io/etcd/pull/10301) to `etcdctl snapshot
-  save`.
-  - User can specify timeout of `etcdctl snapshot save` command using flag `--command-timeout`.
-  - Fix etcdctl to [strip out insecure endpoints from DNS SRV records when using discovery](https://github.com/etcd-io/etcd/pull/10443)
-
-### gRPC proxy
-
-- Fix [etcd server panic from restore operation](https://github.com/etcd-io/etcd/pull/9775).
-  - Let's assume that a watcher had been requested with a future revision X and sent to node A that became network-partitioned thereafter. Meanwhile, cluster makes progress. Then when the partition gets removed, the leader sends a snapshot to node A. Previously if the snapshot's latest revision is still lower than the watch revision X,  **etcd server panicked** during snapshot restore operation.
-  - Especially, gRPC proxy was affected, since it detects a leader loss with a key `"proxy-namespace__lostleader"` and a watch revision `"int64(math.MaxInt64 - 2)"`.
-  - Now, this server-side panic has been fixed.
-- Fix [memory leak in cache layer](https://github.com/etcd-io/etcd/pull/10327).
-- Change [gRPC proxy to expose etcd server endpoint /metrics](https://github.com/etcd-io/etcd/pull/10618).
-  - The metrics that were exposed via the proxy were not etcd server members but instead the proxy itself.
-
-### gRPC gateway
-
-- Replace [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway) endpoint `/v3beta` with [`/v3`](https://github.com/etcd-io/etcd/pull/9298).
-  - Deprecated [`/v3alpha`](https://github.com/etcd-io/etcd/pull/9298).
-  - To deprecate [`/v3beta`](https://github.com/etcd-io/etcd/issues/9189) in v3.5.
-  - In v3.4, `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` still works as a fallback to `curl -L http://localhost:2379/v3/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'`, but `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` won't work in v3.5. Use `curl -L http://localhost:2379/v3/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` instead.
-- Add API endpoints [`/{v3beta,v3}/lease/leases, /{v3beta,v3}/lease/revoke, /{v3beta,v3}/lease/timetolive`](https://github.com/etcd-io/etcd/pull/9450).
-  - To deprecate [`/{v3beta,v3}/kv/lease/leases, /{v3beta,v3}/kv/lease/revoke, /{v3beta,v3}/kv/lease/timetolive`](https://github.com/etcd-io/etcd/issues/9430) in v3.5.
-- Support [`etcd --cors`](https://github.com/etcd-io/etcd/pull/9490) in v3 HTTP requests (gRPC gateway).
-
-### Package `raft`
-
-- Fix [deadlock during PreVote migration process](https://github.com/etcd-io/etcd/pull/8525).
-- Add [`raft.ErrProposalDropped`](https://github.com/etcd-io/etcd/pull/9067).
-  - Now [`(r *raft) Step` returns `raft.ErrProposalDropped`](https://github.com/etcd-io/etcd/pull/9137) if a proposal has been ignored.
-  - e.g. a node is removed from cluster, or [`raftpb.MsgProp` arrives at current leader while there is an ongoing leadership transfer](https://github.com/etcd-io/etcd/issues/8975).
-- Improve [Raft `becomeLeader` and `stepLeader`](https://github.com/etcd-io/etcd/pull/9073) by keeping track of latest `pb.EntryConfChange` index.
-  - Previously record `pendingConf` boolean field scanning the entire tail of the log, which can delay hearbeat send.
-- Fix [missing learner nodes on `(n *node) ApplyConfChange`](https://github.com/etcd-io/etcd/pull/9116).
-- Add [`raft.Config.MaxUncommittedEntriesSize`](https://github.com/etcd-io/etcd/pull/10167) to limit the total size of the uncommitted entries in bytes.
-  - Once exceeded, raft returns `raft.ErrProposalDropped` error.
-  - Prevent [unbounded Raft log growth](https://github.com/cockroachdb/cockroach/issues/27772).
-  - There was a bug in [PR#10167](https://github.com/etcd-io/etcd/pull/10167) but fixed via [PR#10199](https://github.com/etcd-io/etcd/pull/10199).
-- Add [`raft.Ready.CommittedEntries` pagination using `raft.Config.MaxSizePerMsg`](https://github.com/etcd-io/etcd/pull/9982).
-  - This prevents out-of-memory errors if the raft log has become very large and commits all at once.
-  - Fix [correctness bug in CommittedEntries pagination](https://github.com/etcd-io/etcd/pull/10063).
-- Optimize [message send flow control](https://github.com/etcd-io/etcd/pull/9985).
-  - Leader now sends more append entries if it has more non-empty entries to send after updating flow control information.
-  - Now, Raft allows multiple in-flight append messages.
-- Optimize [memory allocation when boxing slice in `maybeCommit`](https://github.com/etcd-io/etcd/pull/10679).
-  - By boxing a heap-allocated slice header instead of the slice header on the stack, we can avoid an allocation when passing through the sort.Interface interface.
-- Avoid [memory allocation in Raft entry `String` method](https://github.com/etcd-io/etcd/pull/10680).
-- Avoid [multiple memory allocations when merging stable and unstable log](https://github.com/etcd-io/etcd/pull/10684).
-- Extract [progress tracking into own component](https://github.com/etcd-io/etcd/pull/10683).
-  - Add [package `raft/tracker`](https://github.com/etcd-io/etcd/pull/10807).
-  - Optimize [string representation of `Progress`](https://github.com/etcd-io/etcd/pull/10882).
-- Make [relationship between `node` and `RawNode` explicit](https://github.com/etcd-io/etcd/pull/10803).
-- Prevent [learners from becoming leader](https://github.com/etcd-io/etcd/pull/10822).
-- Add [package `raft/quorum` to reason about committed indexes as well as vote outcomes for both majority and joint quorums](https://github.com/etcd-io/etcd/pull/10779).
-  - Bundle [Voters and Learner into `raft/tracker.Config` struct](https://github.com/etcd-io/etcd/pull/10865).
-- Use [membership sets in progress tracking](https://github.com/etcd-io/etcd/pull/10779).
-- Implement [joint quorum computation](https://github.com/etcd-io/etcd/pull/10779).
-- Refactor [`raft/node.go` to centralize configuration change application](https://github.com/etcd-io/etcd/pull/10865).
-- Allow [voter to become learner through snapshot](https://github.com/etcd-io/etcd/pull/10864).
-- Add [package `raft/confchange` to internally support joint consensus](https://github.com/etcd-io/etcd/pull/10779).
-- Use [`RawNode` for node's event loop](https://github.com/etcd-io/etcd/pull/10892).
-- Add [`RawNode.Bootstrap` method](https://github.com/etcd-io/etcd/pull/10892).
-- Add [`raftpb.ConfChangeV2` to use joint quorums](https://github.com/etcd-io/etcd/pull/10914).
-  - `raftpb.ConfChange` continues to work as today: it allows carrying out a single configuration change. A `pb.ConfChange` proposal gets added to the Raft log as such and is thus also observed by the app during Ready handling, and fed back to ApplyConfChange.
-  - `raftpb.ConfChangeV2` allows joint configuration changes but will continue to carry out configuration changes in "one phase" (i.e. without ever entering a joint config) when this is possible.
-  - `raftpb.ConfChangeV2` messages initiate configuration changes. They support both the simple "one at a time" membership change protocol and full Joint Consensus allowing for arbitrary changes in membership.
-- Change [`raftpb.ConfState.Nodes` to `raftpb.ConfState.Voters`](https://github.com/etcd-io/etcd/pull/10914).
-
-### Package `wal`
-
-- Add [`Verify` function to perform corruption check on WAL contents](https://github.com/etcd-io/etcd/pull/10603).
-- Fix [`wal` directory cleanup on creation failures](https://github.com/etcd-io/etcd/pull/10689).
-
-### Tooling
-
-- Add [`etcd-dump-logs --entry-type`](https://github.com/etcd-io/etcd/pull/9628) flag to support WAL log filtering by entry type.
-- Add [`etcd-dump-logs --stream-decoder`](https://github.com/etcd-io/etcd/pull/9790) flag to support custom decoder.
-
-### Go
-
-- Require [*Go 1.12+*](https://github.com/etcd-io/etcd/pull/10045).
-- Compile with [*Go 1.12*](https://golang.org/doc/devel/release.html#go1.12).
-
-### Dockerfile
-
-- [Rebase etcd image from Alpine to Debian](https://github.com/etcd-io/etcd/pull/10805) to improve security and maintenance effort for etcd release.
-
-<hr>
-

CHANGELOG-3.5.md

@@ -1,80 +0,0 @@
-
-
-Previous change logs can be found at [CHANGELOG-3.4](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.4.md).
-
-
-<hr>
-
-
-## v3.5.0 (TBD)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.4.0...v3.5.0) and [v3.5 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_5.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v3.5 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_3_5.md).**
-
-### Breaking Changes
-
-- [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway) only supports [`/v3`](TODO) endpoint.
-  - Deprecated [`/v3beta`](https://github.com/etcd-io/etcd/pull/9298).
-  - `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` does work in v3.5. Use `curl -L http://localhost:2379/v3/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` instead.
-- **`etcd --experimental-enable-v2v3` flag has been deprecated.** Use **`etcd --enable-v2v3`** instead.
-  - Change [`etcd --experimental-enable-v2v3`](TODO) flag to `etcd --enable-v2v3`; v2 storage emulation is now stable.
-- **`etcd --debug` flag has been deprecated.** Use **`etcd --log-level=debug`** instead.
-- Remove [`embed.Config.Debug`](https://github.com/etcd-io/etcd/pull/10947).
-- **`etcd --log-output` flag has been deprecated.** Use **`etcd --log-outputs`** instead.
-- **`etcd --logger=zap --log-outputs=stderr`** is now the default.
-- **`etcd --logger=capnslog` flag value has been deprecated.**
-- **`etcd --logger=zap --log-outputs=default` flag value is not supported.**.
-  - Use `etcd --logger=zap --log-outputs=stderr`.
-  - Or, use `etcd --logger=zap --log-outputs=systemd/journal` to send logs to the local systemd journal.
-  - Previously, if etcd parent process ID (PPID) is 1 (e.g. run with systemd), `etcd --logger=capnslog --log-outputs=default` redirects server logs to local systemd journal. And if write to journald fails, it writes to `os.Stderr` as a fallback.
-  - However, even with PPID 1, it can fail to dial systemd journal (e.g. run embedded etcd with Docker container). Then, [every single log write will fail](https://github.com/etcd-io/etcd/pull/9729) and fall back to `os.Stderr`, which is inefficient.
-  - To avoid this problem, systemd journal logging must be configured manually.
-- **`etcd --log-outputs=stderr`** is now the default.
-- **`etcd --log-package-levels` flag for `capnslog` has been deprecated.** Now, **`etcd --logger=zap --log-outputs=stderr`** is the default.
-- **`[CLIENT-URL]/config/local/log` endpoint has been deprecated, as is `etcd --log-package-levels` flag.**
-  - `curl http://127.0.0.1:2379/config/local/log -XPUT -d '{"Level":"DEBUG"}'` won't work.
-  - Please use `etcd --logger=zap --log-outputs=stderr` instead.
-- Deprecated `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metric. Use `etcd_mvcc_db_total_size_in_bytes` instead.
-- Deprecated `etcd_debugging_mvcc_put_total` Prometheus metric. Use `etcd_mvcc_put_total` instead.
-- Deprecated `etcd_debugging_mvcc_delete_total` Prometheus metric. Use `etcd_mvcc_delete_total` instead.
-- Deprecated `etcd_debugging_mvcc_txn_total` Prometheus metric. Use `etcd_mvcc_txn_total` instead.
-- Deprecated `etcd_debugging_mvcc_range_total` Prometheus metric. Use `etcd_mvcc_range_total` instead.
-- Master branch `/version` outputs `3.5.0-pre`, instead of `3.4.0+git`.
-
-### Metrics, Monitoring
-
-Note that any `etcd_debugging_*` metrics are experimental and subject to change.
-
-- Deprecated `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metric. Use `etcd_mvcc_db_total_size_in_bytes` instead.
-- Deprecated `etcd_debugging_mvcc_put_total` Prometheus metric. Use `etcd_mvcc_put_total` instead.
-- Deprecated `etcd_debugging_mvcc_delete_total` Prometheus metric. Use `etcd_mvcc_delete_total` instead.
-- Deprecated `etcd_debugging_mvcc_txn_total` Prometheus metric. Use `etcd_mvcc_txn_total` instead.
-- Deprecated `etcd_debugging_mvcc_range_total` Prometheus metric. Use `etcd_mvcc_range_total` instead.
-
-### etcd server
-
-- [`etcd --enable-v2v3`](TODO) flag is now stable.
-  - `etcd --experimental-enable-v2v3` has been deprecated.
-  - Added [more v2v3 integration tests](https://github.com/etcd-io/etcd/pull/9634).
-  - `etcd --enable-v2=true --enable-v2v3=''` by default, to enable v2 API server that is backed by **v2 store**.
-  - `etcd --enable-v2=true --enable-v2v3=/aaa` to enable v2 API server that is backed by **v3 storage**.
-  - `etcd --enable-v2=false --enable-v2v3=''` to disable v2 API server.
-  - `etcd --enable-v2=false --enable-v2v3=/aaa` to disable v2 API server. TODO: error?
-  - Automatically [create parent directory if it does not exist](https://github.com/etcd-io/etcd/pull/9626) (fix [issue#9609](https://github.com/etcd-io/etcd/issues/9609)).
-  - v4.0 will configure `etcd --enable-v2=true --enable-v2v3=/aaa` to enable v2 API server that is backed by **v3 storage**.
-
-### Package `embed`
-
-- Remove [`embed.Config.Debug`](https://github.com/etcd-io/etcd/pull/10947).
-  - Use `embed.Config.LogLevel` instead.
-
-### gRPC gateway
-
-- [gRPC gateway](https://github.com/grpc-ecosystem/grpc-gateway) only supports [`/v3`](TODO) endpoint.
-  - Deprecated [`/v3beta`](https://github.com/etcd-io/etcd/pull/9298).
-  - `curl -L http://localhost:2379/v3beta/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` does work in v3.5. Use `curl -L http://localhost:2379/v3/kv/put -X POST -d '{"key": "Zm9v", "value": "YmFy"}'` instead.
-
-
-<hr>
-

CHANGELOG-4.0.md

@@ -1,48 +0,0 @@
-
-
-Previous change logs can be found at [CHANGELOG-3.x](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.x.md).
-
-
-<hr>
-
-
-## v4.0.0 (TBD)
-
-See [code changes](https://github.com/etcd-io/etcd/compare/v3.5.0...v4.0.0) and [v4.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_4_0.md) for any breaking changes.
-
-**Again, before running upgrades from any previous release, please make sure to read change logs below and [v4.0 upgrade guide](https://github.com/etcd-io/etcd/blob/master/Documentation/upgrades/upgrade_4_0.md).**
-
-### Breaking Changes
-
-- [Secure etcd by default](https://github.com/etcd-io/etcd/issues/9475)?
-- Change `/health` endpoint output.
-  - Previously, `{"health":"true"}`.
-  - Now, `{"health":true}`.
-  - Breaks [Kubernetes `kubectl get componentstatuses` command](https://github.com/kubernetes/kubernetes/issues/58240).
-- Deprecate [`etcd --proxy*`](TODO) flags; **no more v2 proxy**.
-- Deprecate [v2 storage backend](https://github.com/etcd-io/etcd/issues/9232); **no more v2 store**.
-  - v2 API is still supported via [v2 emulation](TODO).
-- Deprecate [`etcdctl backup`](TODO) command.
-- `clientv3.Client.KeepAlive(ctx context.Context, id LeaseID) (<-chan *LeaseKeepAliveResponse, error)` is now [`clientv4.Client.KeepAlive(ctx context.Context, id LeaseID) <-chan *LeaseKeepAliveResponse`](TODO).
-  - Similar to `Watch`, [`KeepAlive` does not return errors](https://github.com/etcd-io/etcd/issues/7488).
-  - If there's an unknown server error, kill all open channels and create a new stream on the next `KeepAlive` call.
-- Rename `github.com/coreos/client` to `github.com/coreos/clientv2`.
-- [`etcd --experimental-initial-corrupt-check`](TODO) has been  deprecated.
-  - Use [`etcd --initial-corrupt-check`](TODO) instead.
-- [`etcd --experimental-corrupt-check-time`](TODO) has been  deprecated.
-  - Use [`etcd --corrupt-check-time`](TODO) instead.
-
-### etcd server
-
-- [`etcd --initial-corrupt-check`](TODO) flag is now stable (`etcd --experimental-initial-corrupt-check` has been  deprecated).
-  - `etcd --initial-corrupt-check=true` by default, to check cluster database hashes before serving client/peer traffic.
-- [`etcd --corrupt-check-time`](TODO) flag is now stable (`etcd --experimental-corrupt-check-time` has been  deprecated).
-  - `etcd --corrupt-check-time=12h` by default, to check cluster database hashes for every 12-hour.
-
-### Go
-
-- Require [*Go 2*](https://blog.golang.org/go2draft)?
-
-
-<hr>
-

Documentation/demo.md

@@ -271,7 +271,10 @@ etcdctl --endpoints=$ENDPOINTS endpoint health
 
 <img src="https://storage.googleapis.com/etcd/demo/11_etcdctl_snapshot_2016051001.gif" alt="11_etcdctl_snapshot_2016051001"/>
 
+Snapshot can only be requested from one etcd node, so `--endpoints` flag should contain only one endpoint.
+
 ```
+ENDPOINTS=$HOST_1:2379
 etcdctl --endpoints=$ENDPOINTS snapshot save my.db
 
 Snapshot saved at my.db

Documentation/dev-internal/release.md

@@ -63,7 +63,6 @@ All releases version numbers follow the format of [semantic versioning 2.0.0](ht
 
 ## Build release binaries and images
 
-- Ensure `acbuild` is available.
 - Ensure `docker` is available.
 
 Run release script in root directory:

Documentation/faq.md

@@ -72,7 +72,7 @@ etcdctl provides a `snapshot` command to create backups. See [backup][backup] fo
 
 When replacing an etcd node, it's important  to remove the member first and then add its replacement.
 
-etcd employs distributed consensus based on a quorum model; (n+1)/2 members, a majority, must agree on a proposal before it can be committed to the cluster. These proposals include key-value updates and membership changes. This model totally avoids any possibility of split brain inconsistency. The downside is permanent quorum loss is catastrophic.
+etcd employs distributed consensus based on a quorum model; (n/2)+1 members, a majority, must agree on a proposal before it can be committed to the cluster. These proposals include key-value updates and membership changes. This model totally avoids any possibility of split brain inconsistency. The downside is permanent quorum loss is catastrophic.
 
 How this applies to membership: If a 3-member cluster has 1 downed member, it can still make forward progress because the quorum is 2 and 2 members are still live. However, adding a new member to a 3-member cluster will increase the quorum to 3 because 3 votes are required for a majority of 4 members. Since the quorum increased, this extra member buys nothing in terms of fault tolerance; the cluster is still one node failure away from being unrecoverable.
 

Documentation/learning/design-learner.md

@@ -13,26 +13,34 @@ Background
 
 Membership reconfiguration has been one of the biggest operational challenges. Let’s review common challenges.
 
+### 1. New Cluster member overloads Leader
 A newly joined etcd member starts with no data, thus demanding more updates from leader until it catches up with leader’s logs. Then leader’s network is more likely to be overloaded, blocking or dropping leader heartbeats to followers. In such case, a follower may election-timeout to start a new leader election. That is, a cluster with a new member is more vulnerable to leader election. Both leader election and the subsequent update propagation to the new member are prone to causing periods of cluster unavailability (see *Figure 1*).
 
 ![server-learner-figure-01](img/server-learner-figure-01.png)
 
+### 2. Network Partitions scenarios
 What if network partition happens? It depends on leader partition. If the leader still maintains the active quorum, the cluster would continue to operate (see *Figure 2*).
 
 ![server-learner-figure-02](img/server-learner-figure-02.png)
 
+#### 2.1 Leader isolation
 What if the leader becomes isolated from the rest of the cluster? Leader monitors progress of each follower. When leader loses connectivity from the quorum, it reverts back to follower which will affect the cluster availability (see *Figure 3*).
 
 ![server-learner-figure-03](img/server-learner-figure-03.png)
 
-When a new node is added to 3 node cluster, the cluster size becomes 4 and the quorum size becomes 3. What if a new node had joined the cluster, and then network partition happens? It depends on which partition the new member gets located after partition. If the new node happens to be located in the same partition as leader’s, the leader still maintains the active quorum of 3. No leadership election happens, and no cluster availability gets affected (see *Figure 4*).
+When a new node is added to 3 node cluster, the cluster size becomes 4 and the quorum size becomes 3. What if a new node had joined the cluster, and then network partition happens? It depends on which partition the new member gets located after partition. 
+
+#### 2.2 Cluster Split 3+1
+If the new node happens to be located in the same partition as leader’s, the leader still maintains the active quorum of 3. No leadership election happens, and no cluster availability gets affected (see *Figure 4*).
 
 ![server-learner-figure-04](img/server-learner-figure-04.png)
 
+#### 2.3 Cluster Split 2+2
 If the cluster is 2-and-2 partitioned, then neither of partition maintains the quorum of 3. In this case, leadership election happens (see *Figure 5*).
 
 ![server-learner-figure-05](img/server-learner-figure-05.png)
 
+#### 2.4 Quorum Lost
 What if network partition happens first, and then a new member gets added? A partitioned 3-node cluster already has one disconnected follower. When a new member is added, the quorum changes from 2 to 3. Now, this cluster has only 2 active nodes out 4, thus losing quorum and starting a new leadership election (see *Figure 6*).
 
 ![server-learner-figure-06](img/server-learner-figure-06.png)
@@ -43,6 +51,7 @@ Adding a new member to a 1-node cluster changes the quorum size to 2, immediatel
 
 ![server-learner-figure-07](img/server-learner-figure-07.png)
 
+### 3. Cluster Misconfigurations
 An even worse case is when an added member is misconfigured. Membership reconfiguration is a two-step process: “etcdctl member add” and starting an etcd server process with the given peer URL. That is, “member add” command is applied regardless of URL, even when the URL value is invalid. If the first step is applied with invalid URLs, the second step cannot even start the new etcd. Once the cluster loses quorum, there is no way to revert the membership change (see *Figure 8*).
 
 ![server-learner-figure-08](img/server-learner-figure-08.png)

Documentation/op-guide/configuration.md

@@ -446,6 +446,11 @@ Follow the instructions when using these flags.
 + default: 0s
 + env variable: ETCD_EXPERIMENTAL_CORRUPT_CHECK_TIME
 
+### --experimental-compaction-batch-limit
++ Sets the maximum revisions deleted in each compaction batch.
++ default: 1000
++ env variable: ETCD_EXPERIMENTAL_COMPACTION_BATCH_LIMIT
+
 [build-cluster]: clustering.md#static
 [reconfig]: runtime-configuration.md
 [discovery]: clustering.md#discovery

Documentation/op-guide/runtime-configuration.md

@@ -126,7 +126,7 @@ If adding multiple members the best practice is to configure a single member at
 #### Add a new member as learner
 
 Starting from v3.4, etcd supports adding a new member as learner / non-voting member.
-The motivation and design can be found in [design doc](https://etcd.readthedocs.io/en/latest/server-learner.html).
+The motivation and design can be found in [design doc][design-learner].
 In order to make the process of adding a new member safer,
 and to reduce cluster downtime when the new member is added, it is recommended that the new member is added to cluster
 as a learner until it catches up. This can be described as a three step process:
@@ -243,3 +243,4 @@ It is enabled by default.
 [remove member]: #remove-a-member
 [runtime-reconf]: runtime-reconf-design.md
 [error cases when promoting a member]: #error-cases-when-promoting-a-learner-member
+[design-learner]: ../learning/design-learner.md

Documentation/upgrades/upgrade_3_3.md

@@ -369,6 +369,52 @@ After
 docker pull gcr.io/etcd-development/etcd:v3.3.0
 ```
 
+### Upgrades to >= v3.3.14
+
+[v3.3.14](https://github.com/etcd-io/etcd/releases/tag/v3.3.14) had to include some features from 3.4, while trying to minimize the difference between client balancer implementation. This release fixes ["kube-apiserver 1.13.x refuses to work when first etcd-server is not available" (kubernetes#72102)](https://github.com/kubernetes/kubernetes/issues/72102).
+
+`grpc.ErrClientConnClosing` has been [deprecated in gRPC >= 1.10](https://github.com/grpc/grpc-go/pull/1854).
+
+```diff
+import (
++	"go.etcd.io/etcd/clientv3"
+
+	"google.golang.org/grpc"
++	"google.golang.org/grpc/codes"
++	"google.golang.org/grpc/status"
+)
+
+_, err := kvc.Get(ctx, "a")
+-if err == grpc.ErrClientConnClosing {
++if clientv3.IsConnCanceled(err) {
+
+// or
++s, ok := status.FromError(err)
++if ok {
++  if s.Code() == codes.Canceled
+```
+
+[The new client balancer](https://github.com/etcd-io/etcd/blob/master/Documentation/learning/design-client.md) uses an asynchronous resolver to pass endpoints to the gRPC dial function. As a result, [v3.3.14](https://github.com/etcd-io/etcd/releases/tag/v3.3.14) or later requires `grpc.WithBlock` dial option to wait until the underlying connection is up.
+
+```diff
+import (
+	"time"
+	"go.etcd.io/etcd/clientv3"
++	"google.golang.org/grpc"
+)
+
++// "grpc.WithBlock()" to block until the underlying connection is up
+ccfg := clientv3.Config{
+  Endpoints:            []string{"localhost:2379"},
+  DialTimeout:          time.Second,
++ DialOptions:          []grpc.DialOption{grpc.WithBlock()},
+  DialKeepAliveTime:    time.Second,
+  DialKeepAliveTimeout: 500 * time.Millisecond,
+}
+```
+
+Please see [CHANGELOG](https://github.com/etcd-io/etcd/blob/master/CHANGELOG-3.3.md) for a full list of changes.
+
 ### Server upgrade checklists
 
 #### Upgrade requirements

Documentation/upgrades/upgrade_3_4.md

@@ -35,6 +35,21 @@ OK
 +etcdctl put foo bar
 ```
 
+#### Make `etcd --enable-v2=false` default
+
+[`etcd --enable-v2=false`](https://github.com/etcd-io/etcd/pull/10935) is now the default.
+
+This means, unless `etcd --enable-v2=true` is specified, etcd v3.4 server would not serve v2 API requests.
+
+If v2 API were used, make sure to enable v2 API in v3.4:
+
+```diff
+-etcd
++etcd --enable-v2=true
+```
+
+Other HTTP APIs will still work (e.g. `[CLIENT-URL]/metrics`, `[CLIENT-URL]/health`, v3 gRPC gateway).
+
 #### Deprecated `etcd --ca-file` and `etcd --peer-ca-file` flags
 
 `--ca-file` and `--peer-ca-file` flags are deprecated; they have been deprecated since v2.1.
@@ -49,6 +64,50 @@ OK
 +etcd --peer-trusted-ca-file ca-peer.crt
 ```
 
+#### Deprecated `grpc.ErrClientConnClosing` error
+
+`grpc.ErrClientConnClosing` has been [deprecated in gRPC >= 1.10](https://github.com/grpc/grpc-go/pull/1854).
+
+```diff
+import (
++	"go.etcd.io/etcd/clientv3"
+
+	"google.golang.org/grpc"
++	"google.golang.org/grpc/codes"
++	"google.golang.org/grpc/status"
+)
+
+_, err := kvc.Get(ctx, "a")
+-if err == grpc.ErrClientConnClosing {
++if clientv3.IsConnCanceled(err) {
+
+// or
++s, ok := status.FromError(err)
++if ok {
++  if s.Code() == codes.Canceled
+```
+
+#### Require `grpc.WithBlock` for client dial
+
+[The new client balancer](https://github.com/etcd-io/etcd/blob/master/Documentation/learning/design-client.md) uses an asynchronous resolver to pass endpoints to the gRPC dial function. As a result, v3.4 client requires `grpc.WithBlock` dial option to wait until the underlying connection is up.
+
+```diff
+import (
+	"time"
+	"go.etcd.io/etcd/clientv3"
++	"google.golang.org/grpc"
+)
+
++// "grpc.WithBlock()" to block until the underlying connection is up
+ccfg := clientv3.Config{
+  Endpoints:            []string{"localhost:2379"},
+  DialTimeout:          time.Second,
++ DialOptions:          []grpc.DialOption{grpc.WithBlock()},
+  DialKeepAliveTime:    time.Second,
+  DialKeepAliveTimeout: 500 * time.Millisecond,
+}
+```
+
 #### Deprecating `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metrics
 
 v3.4 promotes `etcd_debugging_mvcc_db_total_size_in_bytes` Prometheus metrics to `etcd_mvcc_db_total_size_in_bytes`, in order to encourage etcd storage monitoring.

Documentation/v2/dev/release.md

@@ -53,7 +53,6 @@ All releases version numbers follow the format of [semantic versioning 2.0.0](ht
 
 ## Build Release Binaries and Images
 
-- Ensure `acbuild` is available.
 - Ensure `docker` is available.
 
 Run release script in root directory:
@@ -74,8 +73,6 @@ The following commands are used for public release sign:
 cd release
 # personal GPG is okay for now
 for i in etcd-*{.zip,.tar.gz}; do gpg --sign ${i}; done
-# use `CoreOS ACI Builder <release@coreos.com>` secret key
-for aci in etcd-${VERSION}.*.aci; do gpg -u 88182190 -a --output ${aci}.asc --detach-sig ${aci}; done
 ```
 
 ## Publish Release Page in GitHub

Makefile

@@ -51,7 +51,7 @@ docker-remove:
 
 
 
-GO_VERSION ?= 1.12.7
+GO_VERSION ?= 1.12.9
 ETCD_VERSION ?= $(shell git rev-parse --short HEAD || echo "GitNotFound")
 
 TEST_SUFFIX = $(shell date +%s | base64 | head -c 15)
@@ -65,11 +65,11 @@ endif
 
 
 # Example:
-#   GO_VERSION=1.10.7 make build-docker-test
+#   GO_VERSION=1.12.9 make build-docker-test
 #   make build-docker-test
 #
 #   gcloud docker -- login -u _json_key -p "$(cat /etc/gcp-key-etcd-development.json)" https://gcr.io
-#   GO_VERSION=1.10.7 make push-docker-test
+#   GO_VERSION=1.12.9 make push-docker-test
 #   make push-docker-test
 #
 #   gsutil -m acl ch -u allUsers:R -r gs://artifacts.etcd-development.appspot.com
@@ -104,7 +104,7 @@ compile-with-docker-test:
 	  --rm \
 	  --mount type=bind,source=`pwd`,destination=/go/src/go.etcd.io/etcd \
 	  gcr.io/etcd-development/etcd-test:go$(GO_VERSION) \
-	  /bin/bash -c "GO_BUILD_FLAGS=-v ./build && ./bin/etcd --version"
+	  /bin/bash -c "GO_BUILD_FLAGS=-v GOOS=linux GOARCH=amd64 ./build && ./bin/etcd --version"
 
 compile-setup-gopath-with-docker-test:
 	$(info GO_VERSION: $(GO_VERSION))
@@ -112,7 +112,7 @@ compile-setup-gopath-with-docker-test:
 	  --rm \
 	  --mount type=bind,source=`pwd`,destination=/etcd \
 	  gcr.io/etcd-development/etcd-test:go$(GO_VERSION) \
-	  /bin/bash -c "cd /etcd && ETCD_SETUP_GOPATH=1 GO_BUILD_FLAGS=-v ./build && ./bin/etcd --version && rm -rf ./gopath"
+	  /bin/bash -c "cd /etcd && ETCD_SETUP_GOPATH=1 GO_BUILD_FLAGS=-v GOOS=linux GOARCH=amd64 ./build && ./bin/etcd --version && rm -rf ./gopath"
 
 
 

ROADMAP.md

@@ -1,21 +0,0 @@
-#  etcd roadmap
-
-**work in progress**
-
-This document defines a high level roadmap for etcd development.
-
-The dates below should not be considered authoritative, but rather indicative of the projected timeline of the project. The [milestones defined in GitHub](https://github.com/etcd-io/etcd/milestones) represent the most up-to-date and issue-for-issue plans.
-
-etcd 3.3 is our current stable branch. The roadmap below outlines new features that will be added to etcd, and while subject to change, define what future stable will look like.
-
-### etcd 3.4 (2019)
-
-- Stabilization of 3.3 experimental features
-- Support/document downgrade
-- Snapshot restore as Go library
-- Improved client balancer with new gRPC balancer interface
-- Improve single-client put performance
-- Improve large response handling
-- Improve test coverage
-- Decrease test runtime
-- Migrate to Go module for dependency management

auth/store.go

@@ -388,7 +388,7 @@ func (as *authStore) UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse,
 	var hashed []byte
 	var err error
 
-	if !r.Options.NoPassword {
+	if r.Options != nil && !r.Options.NoPassword {
 		hashed, err = bcrypt.GenerateFromPassword([]byte(r.Password), as.bcryptCost)
 		if err != nil {
 			if as.lg != nil {

clientv3/client.go

@@ -129,8 +129,12 @@ func NewFromURLs(urls []string) (*Client, error) {
 // Close shuts down the client's etcd connections.
 func (c *Client) Close() error {
 	c.cancel()
-	c.Watcher.Close()
-	c.Lease.Close()
+	if c.Watcher != nil {
+		c.Watcher.Close()
+	}
+	if c.Lease != nil {
+		c.Lease.Close()
+	}
 	if c.resolverGroup != nil {
 		c.resolverGroup.Close()
 	}
@@ -274,8 +278,8 @@ func (c *Client) getToken(ctx context.Context) error {
 	var err error // return last error in a case of fail
 	var auth *authenticator
 
-	for i := 0; i < len(c.cfg.Endpoints); i++ {
-		ep := c.cfg.Endpoints[i]
+	eps := c.Endpoints()
+	for _, ep := range eps {
 		// use dial options without dopts to avoid reusing the client balancer
 		var dOpts []grpc.DialOption
 		_, host, _ := endpoint.ParseEndpoint(ep)
@@ -519,13 +523,17 @@ func (c *Client) roundRobinQuorumBackoff(waitBetween time.Duration, jitterFracti
 
 func (c *Client) checkVersion() (err error) {
 	var wg sync.WaitGroup
-	errc := make(chan error, len(c.cfg.Endpoints))
+
+	eps := c.Endpoints()
+	errc := make(chan error, len(eps))
 	ctx, cancel := context.WithCancel(c.ctx)
 	if c.cfg.DialTimeout > 0 {
-		ctx, cancel = context.WithTimeout(ctx, c.cfg.DialTimeout)
+		cancel()
+		ctx, cancel = context.WithTimeout(c.ctx, c.cfg.DialTimeout)
 	}
-	wg.Add(len(c.cfg.Endpoints))
-	for _, ep := range c.cfg.Endpoints {
+
+	wg.Add(len(eps))
+	for _, ep := range eps {
 		// if cluster is current, any endpoint gives a recent version
 		go func(e string) {
 			defer wg.Done()
@@ -537,8 +545,15 @@ func (c *Client) checkVersion() (err error) {
 			vs := strings.Split(resp.Version, ".")
 			maj, min := 0, 0
 			if len(vs) >= 2 {
-				maj, _ = strconv.Atoi(vs[0])
-				min, rerr = strconv.Atoi(vs[1])
+				var serr error
+				if maj, serr = strconv.Atoi(vs[0]); serr != nil {
+					errc <- serr
+					return
+				}
+				if min, serr = strconv.Atoi(vs[1]); serr != nil {
+					errc <- serr
+					return
+				}
 			}
 			if maj < 3 || (maj == 3 && min < 2) {
 				rerr = ErrOldCluster
@@ -547,7 +562,7 @@ func (c *Client) checkVersion() (err error) {
 		}(ep)
 	}
 	// wait for success
-	for i := 0; i < len(c.cfg.Endpoints); i++ {
+	for range eps {
 		if err = <-errc; err == nil {
 			break
 		}
@@ -587,10 +602,13 @@ func isUnavailableErr(ctx context.Context, err error) bool {
 	if err == nil {
 		return false
 	}
-	ev, _ := status.FromError(err)
-	// Unavailable codes mean the system will be right back.
-	// (e.g., can't connect, lost leader)
-	return ev.Code() == codes.Unavailable
+	ev, ok := status.FromError(err)
+	if ok {
+		// Unavailable codes mean the system will be right back.
+		// (e.g., can't connect, lost leader)
+		return ev.Code() == codes.Unavailable
+	}
+	return false
 }
 
 func toErr(ctx context.Context, err error) error {
@@ -610,9 +628,6 @@ func toErr(ctx context.Context, err error) error {
 			if ctx.Err() != nil {
 				err = ctx.Err()
 			}
-		case codes.Unavailable:
-		case codes.FailedPrecondition:
-			err = grpc.ErrClientConnClosing
 		}
 	}
 	return err
@@ -632,16 +647,19 @@ func IsConnCanceled(err error) bool {
 	if err == nil {
 		return false
 	}
-	// >= gRPC v1.10.x
+
+	// >= gRPC v1.23.x
 	s, ok := status.FromError(err)
 	if ok {
 		// connection is canceled or server has already closed the connection
 		return s.Code() == codes.Canceled || s.Message() == "transport is closing"
 	}
+
 	// >= gRPC v1.10.x
 	if err == context.Canceled {
 		return true
 	}
+
 	// <= gRPC v1.7.x returns 'errors.New("grpc: the client connection is closing")'
 	return strings.Contains(err.Error(), "grpc: the client connection is closing")
 }

clientv3/client_test.go

@@ -156,3 +156,13 @@ func TestIsHaltErr(t *testing.T) {
 		t.Errorf("cancel on context should be Halted")
 	}
 }
+
+func TestCloseCtxClient(t *testing.T) {
+	ctx := context.Background()
+	c := NewCtxClient(ctx)
+	err := c.Close()
+	// Close returns ctx.toErr, a nil error means an open Done channel
+	if err == nil {
+		t.Errorf("failed to Close the client. %v", err)
+	}
+}

clientv3/config.go

@@ -68,6 +68,8 @@ type Config struct {
 	RejectOldCluster bool `json:"reject-old-cluster"`
 
 	// DialOptions is a list of dial options for the grpc client (e.g., for interceptors).
+	// For example, pass "grpc.WithBlock()" to block until the underlying connection is up.
+	// Without this, Dial returns immediately and connecting the server happens in background.
 	DialOptions []grpc.DialOption
 
 	// Context is the default client context; it can be used to cancel grpc dial out and

clientv3/doc.go

@@ -90,7 +90,7 @@
 //		// with etcd clientv3 <= v3.3
 //		if err == context.Canceled {
 //			// grpc balancer calls 'Get' with an inflight client.Close
-//		} else if err == grpc.ErrClientConnClosing {
+//		} else if err == grpc.ErrClientConnClosing { // <= gRCP v1.7.x
 //			// grpc balancer calls 'Get' after client.Close.
 //		}
 //		// with etcd clientv3 >= v3.4

clientv3/integration/kv_test.go

@@ -37,8 +37,8 @@ func TestKVPutError(t *testing.T) {
 	defer testutil.AfterTest(t)
 
 	var (
-		maxReqBytes = 1.5 * 1024 * 1024 // hard coded max in v3_server.go
-		quota       = int64(int(maxReqBytes) + 8*os.Getpagesize())
+		maxReqBytes = 1.5 * 1024 * 1024                                // hard coded max in v3_server.go
+		quota       = int64(int(maxReqBytes*1.2) + 8*os.Getpagesize()) // make sure we have enough overhead in backend quota. See discussion in #6486.
 	)
 	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 1, QuotaBackendBytes: quota, ClientMaxCallSendMsgSize: 100 * 1024 * 1024})
 	defer clus.Terminate(t)
@@ -463,7 +463,7 @@ func TestKVGetErrConnClosed(t *testing.T) {
 		defer close(donec)
 		_, err := cli.Get(context.TODO(), "foo")
 		if !clientv3.IsConnCanceled(err) {
-			t.Errorf("expected %v or %v, got %v", context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, got %v", context.Canceled, err)
 		}
 	}()
 
@@ -490,7 +490,7 @@ func TestKVNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Get(context.TODO(), "foo")
 		if !clientv3.IsConnCanceled(err) {
-			t.Errorf("expected %v or %v, got %v", context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, got %v", context.Canceled, err)
 		}
 		close(donec)
 	}()

clientv3/integration/lease_test.go

@@ -27,8 +27,6 @@ import (
 	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
 	"go.etcd.io/etcd/integration"
 	"go.etcd.io/etcd/pkg/testutil"
-
-	"google.golang.org/grpc"
 )
 
 func TestLeaseNotFoundError(t *testing.T) {
@@ -300,9 +298,8 @@ func TestLeaseGrantErrConnClosed(t *testing.T) {
 		defer close(donec)
 		_, err := cli.Grant(context.TODO(), 5)
 		if !clientv3.IsConnCanceled(err) {
-			// grpc.ErrClientConnClosing if grpc-go balancer calls 'Get' after client.Close.
 			// context.Canceled if grpc-go balancer calls 'Get' with an inflight client.Close.
-			t.Errorf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, or server unavailable, got %v", context.Canceled, err)
 		}
 	}()
 
@@ -372,7 +369,7 @@ func TestLeaseGrantNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Grant(context.TODO(), 5)
 		if !clientv3.IsConnCanceled(err) {
-			t.Errorf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v or server unavailable, got %v", context.Canceled, err)
 		}
 		close(donec)
 	}()
@@ -405,7 +402,7 @@ func TestLeaseRevokeNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Revoke(context.TODO(), leaseID)
 		if !clientv3.IsConnCanceled(err) {
-			t.Fatalf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Fatalf("expected %v or server unavailable, got %v", context.Canceled, err)
 		}
 		close(donec)
 	}()

clientv3/integration/maintenance_test.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"math"
 	"path/filepath"
 	"testing"
 	"time"
@@ -149,7 +150,7 @@ func TestMaintenanceSnapshotErrorInflight(t *testing.T) {
 	clus.Members[0].Stop(t)
 	dpath := filepath.Join(clus.Members[0].DataDir, "member", "snap", "db")
 	b := backend.NewDefaultBackend(dpath)
-	s := mvcc.NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := mvcc.NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, mvcc.StoreConfig{CompactionBatchLimit: math.MaxInt32})
 	rev := 100000
 	for i := 2; i <= rev; i++ {
 		s.Put([]byte(fmt.Sprintf("%10d", i)), bytes.Repeat([]byte("a"), 1024), lease.NoLease)

clientv3/integration/metrics_test.go

@@ -41,12 +41,13 @@ func TestV3ClientMetrics(t *testing.T) {
 	var (
 		addr = "localhost:27989"
 		ln   net.Listener
-		err  error
 	)
 
 	// listen for all Prometheus metrics
 	donec := make(chan struct{})
 	go func() {
+		var err error
+
 		defer close(donec)
 
 		srv := &http.Server{Handler: promhttp.Handler()}
@@ -87,7 +88,7 @@ func TestV3ClientMetrics(t *testing.T) {
 
 	pBefore := sumCountersForMetricAndLabels(t, url, "grpc_client_started_total", "Put", "unary")
 
-	_, err = cli.Put(context.Background(), "foo", "bar")
+	_, err := cli.Put(context.Background(), "foo", "bar")
 	if err != nil {
 		t.Errorf("Error putting value in key store")
 	}

clientv3/snapshot/v3_snapshot.go

@@ -383,7 +383,7 @@ func (s *v3Manager) saveDB() error {
 	// a lessor never timeouts leases
 	lessor := lease.NewLessor(s.lg, be, lease.LessorConfig{MinLeaseTTL: math.MaxInt64})
 
-	mvs := mvcc.NewStore(s.lg, be, lessor, (*initIndex)(&commit))
+	mvs := mvcc.NewStore(s.lg, be, lessor, (*initIndex)(&commit), mvcc.StoreConfig{CompactionBatchLimit: math.MaxInt32})
 	txn := mvs.Write()
 	btx := be.BatchTx()
 	del := func(k, v []byte) error {

embed/config.go

@@ -280,6 +280,7 @@ type Config struct {
 	ExperimentalBackendFreelistType string `json:"experimental-backend-bbolt-freelist-type"`
 	// ExperimentalEnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
 	ExperimentalEnableLeaseCheckpoint bool `json:"experimental-enable-lease-checkpoint"`
+	ExperimentalCompactionBatchLimit  int  `json:"experimental-compaction-batch-limit"`
 
 	// ForceNewCluster starts a new cluster even if previously started; unsafe.
 	ForceNewCluster bool `json:"force-new-cluster"`

embed/config_logging.go

@@ -170,7 +170,10 @@ func (cfg *Config) setupLogging() error {
 		}
 
 		if !isJournal {
-			copied := logutil.AddOutputPaths(logutil.DefaultZapLoggerConfig, outputPaths, errOutputPaths)
+			copied := logutil.DefaultZapLoggerConfig
+			copied.OutputPaths = outputPaths
+			copied.ErrorOutputPaths = errOutputPaths
+			copied = logutil.MergeOutputPaths(copied)
 			copied.Level = zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(cfg.LogLevel))
 			if cfg.Debug || cfg.LogLevel == "debug" {
 				// enable tracing even when "--debug --log-level info"

embed/etcd.go

@@ -205,6 +205,7 @@ func StartEtcd(inCfg *Config) (e *Etcd, err error) {
 		ForceNewCluster:            cfg.ForceNewCluster,
 		EnableGRPCGateway:          cfg.EnableGRPCGateway,
 		EnableLeaseCheckpoint:      cfg.ExperimentalEnableLeaseCheckpoint,
+		CompactionBatchLimit:       cfg.ExperimentalCompactionBatchLimit,
 	}
 	print(e.cfg.logger, *cfg, srvcfg, memberInitialized)
 	if e.Server, err = etcdserver.NewServer(srvcfg); err != nil {

etcdmain/config.go

@@ -255,6 +255,7 @@ func newConfig() *config {
 	fs.StringVar(&cfg.ec.ExperimentalEnableV2V3, "experimental-enable-v2v3", cfg.ec.ExperimentalEnableV2V3, "v3 prefix for serving emulated v2 state.")
 	fs.StringVar(&cfg.ec.ExperimentalBackendFreelistType, "experimental-backend-bbolt-freelist-type", cfg.ec.ExperimentalBackendFreelistType, "ExperimentalBackendFreelistType specifies the type of freelist that boltdb backend uses(array and map are supported types)")
 	fs.BoolVar(&cfg.ec.ExperimentalEnableLeaseCheckpoint, "experimental-enable-lease-checkpoint", false, "Enable to persist lease remaining TTL to prevent indefinite auto-renewal of long lived leases.")
+	fs.IntVar(&cfg.ec.ExperimentalCompactionBatchLimit, "experimental-compaction-batch-limit", cfg.ec.ExperimentalCompactionBatchLimit, "Sets the maximum revisions deleted in each compaction batch.")
 
 	// unsafe
 	fs.BoolVar(&cfg.ec.ForceNewCluster, "force-new-cluster", false, "Force to create a new one member cluster.")

etcdmain/help.go

@@ -200,10 +200,14 @@ Experimental feature:
     Duration of time between cluster corruption check passes.
   --experimental-enable-v2v3 ''
     Serve v2 requests through the v3 backend under a given prefix.
-  --experimental-backend-bbolt-freelist-type
+  --experimental-backend-bbolt-freelist-type 'array'
     ExperimentalBackendFreelistType specifies the type of freelist that boltdb backend uses(array and map are supported types).
-  --experimental-enable-lease-checkpoint
+  --experimental-enable-lease-checkpoint 'false'
     ExperimentalEnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
+  --experimental-compaction-batch-limit 1000
+    ExperimentalCompactionBatchLimit sets the maximum revisions deleted in each compaction batch.
+  --experimental-peer-skip-client-san-verification 'false'
+    Skip verification of SAN field in client certificate for peer connections.
 
 Unsafe feature:
   --force-new-cluster 'false'

etcdserver/api/capability.go

@@ -40,6 +40,7 @@ var (
 		"3.1.0": {AuthCapability: true, V3rpcCapability: true},
 		"3.2.0": {AuthCapability: true, V3rpcCapability: true},
 		"3.3.0": {AuthCapability: true, V3rpcCapability: true},
+		"3.4.0": {AuthCapability: true, V3rpcCapability: true},
 	}
 
 	enableMapMu sync.RWMutex

etcdserver/api/rafthttp/http.go

@@ -258,6 +258,11 @@ func (h *snapshotHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	snapshotReceiveInflights.WithLabelValues(from).Inc()
+	defer func() {
+		snapshotReceiveInflights.WithLabelValues(from).Dec()
+	}()
+
 	if h.lg != nil {
 		h.lg.Info(
 			"receiving database snapshot",

etcdserver/api/rafthttp/metrics.go

@@ -80,6 +80,15 @@ var (
 		[]string{"To"},
 	)
 
+	snapshotSendInflights = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_send_inflights_total",
+		Help:      "Total number of inflight snapshot sends",
+	},
+		[]string{"To"},
+	)
+
 	snapshotSendFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: "etcd",
 		Subsystem: "network",
@@ -111,6 +120,15 @@ var (
 		[]string{"From"},
 	)
 
+	snapshotReceiveInflights = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "network",
+		Name:      "snapshot_receive_inflights_total",
+		Help:      "Total number of inflight snapshot receives",
+	},
+		[]string{"From"},
+	)
+
 	snapshotReceiveFailures = prometheus.NewCounterVec(prometheus.CounterOpts{
 		Namespace: "etcd",
 		Subsystem: "network",
@@ -156,9 +174,11 @@ func init() {
 	prometheus.MustRegister(recvFailures)
 
 	prometheus.MustRegister(snapshotSend)
+	prometheus.MustRegister(snapshotSendInflights)
 	prometheus.MustRegister(snapshotSendFailures)
 	prometheus.MustRegister(snapshotSendSeconds)
 	prometheus.MustRegister(snapshotReceive)
+	prometheus.MustRegister(snapshotReceiveInflights)
 	prometheus.MustRegister(snapshotReceiveFailures)
 	prometheus.MustRegister(snapshotReceiveSeconds)
 

etcdserver/api/rafthttp/snapshot_sender.go

@@ -90,6 +90,11 @@ func (s *snapshotSender) send(merged snap.Message) {
 		plog.Infof("start to send database snapshot [index: %d, to %s]...", m.Snapshot.Metadata.Index, types.ID(m.To))
 	}
 
+	snapshotSendInflights.WithLabelValues(to).Inc()
+	defer func() {
+		snapshotSendInflights.WithLabelValues(to).Dec()
+	}()
+
 	err := s.post(req)
 	defer merged.CloseWithError(err)
 	if err != nil {
@@ -139,7 +144,6 @@ func (s *snapshotSender) send(merged snap.Message) {
 	}
 
 	sentBytes.WithLabelValues(to).Add(float64(merged.TotalSize))
-
 	snapshotSend.WithLabelValues(to).Inc()
 	snapshotSendSeconds.WithLabelValues(to).Observe(time.Since(start).Seconds())
 }

etcdserver/api/v3rpc/watch.go

@@ -179,7 +179,7 @@ func (ws *watchServer) Watch(stream pb.Watch_WatchServer) (err error) {
 				}
 			} else {
 				if sws.lg != nil {
-					sws.lg.Warn("failed to receive watch request from gRPC stream", zap.Error(err))
+					sws.lg.Warn("failed to receive watch request from gRPC stream", zap.Error(rerr))
 				} else {
 					plog.Warningf("failed to receive watch request from gRPC stream (%q)", rerr.Error())
 				}

etcdserver/backend.go

@@ -102,7 +102,7 @@ func openBackend(cfg ServerConfig) backend.Backend {
 // case, replace the db with the snapshot db sent by the leader.
 func recoverSnapshotBackend(cfg ServerConfig, oldbe backend.Backend, snapshot raftpb.Snapshot) (backend.Backend, error) {
 	var cIndex consistentIndex
-	kv := mvcc.New(cfg.Logger, oldbe, &lease.FakeLessor{}, &cIndex)
+	kv := mvcc.New(cfg.Logger, oldbe, &lease.FakeLessor{}, &cIndex, mvcc.StoreConfig{CompactionBatchLimit: cfg.CompactionBatchLimit})
 	defer kv.Close()
 	if snapshot.Metadata.Index <= kv.ConsistentIndex() {
 		return oldbe, nil

etcdserver/config.go

@@ -112,6 +112,7 @@ type ServerConfig struct {
 
 	AutoCompactionRetention time.Duration
 	AutoCompactionMode      string
+	CompactionBatchLimit    int
 	QuotaBackendBytes       int64
 	MaxTxnOps               uint
 

etcdserver/metrics.go

@@ -76,6 +76,12 @@ var (
 		Name:      "slow_apply_total",
 		Help:      "The total number of slow apply requests (likely overloaded from slow disk).",
 	})
+	applySnapshotInProgress = prometheus.NewGauge(prometheus.GaugeOpts{
+		Namespace: "etcd",
+		Subsystem: "server",
+		Name:      "snapshot_apply_in_progress_total",
+		Help:      "1 if the server is applying the incoming snapshot. 0 if none.",
+	})
 	proposalsCommitted = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace: "etcd",
 		Subsystem: "server",
@@ -153,6 +159,7 @@ func init() {
 	prometheus.MustRegister(leaderChanges)
 	prometheus.MustRegister(heartbeatSendFailures)
 	prometheus.MustRegister(slowApplies)
+	prometheus.MustRegister(applySnapshotInProgress)
 	prometheus.MustRegister(proposalsCommitted)
 	prometheus.MustRegister(proposalsApplied)
 	prometheus.MustRegister(proposalsPending)

etcdserver/server.go

@@ -539,7 +539,7 @@ func NewServer(cfg ServerConfig) (srv *EtcdServer, err error) {
 			CheckpointInterval:         cfg.LeaseCheckpointInterval,
 			ExpiredLeasesRetryInterval: srv.Cfg.ReqTimeout(),
 		})
-	srv.kv = mvcc.New(srv.getLogger(), srv.be, srv.lessor, &srv.consistIndex)
+	srv.kv = mvcc.New(srv.getLogger(), srv.be, srv.lessor, &srv.consistIndex, mvcc.StoreConfig{CompactionBatchLimit: cfg.CompactionBatchLimit})
 	if beExist {
 		kvindex := srv.kv.ConsistentIndex()
 		// TODO: remove kvindex != 0 checking when we do not expect users to upgrade
@@ -1113,6 +1113,7 @@ func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
 	if raft.IsEmptySnap(apply.snapshot) {
 		return
 	}
+	applySnapshotInProgress.Inc()
 
 	lg := s.getLogger()
 	if lg != nil {
@@ -1138,6 +1139,7 @@ func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
 		} else {
 			plog.Infof("finished applying incoming snapshot at index %d", ep.snapi)
 		}
+		applySnapshotInProgress.Dec()
 	}()
 
 	if apply.snapshot.Metadata.Index <= ep.appliedi {

etcdserver/server_test.go

@@ -984,7 +984,7 @@ func TestSnapshot(t *testing.T) {
 		r:       *r,
 		v2store: st,
 	}
-	srv.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &srv.consistIndex)
+	srv.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &srv.consistIndex, mvcc.StoreConfig{})
 	srv.be = be
 
 	ch := make(chan struct{}, 2)
@@ -1065,7 +1065,7 @@ func TestSnapshotOrdering(t *testing.T) {
 
 	be, tmpPath := backend.NewDefaultTmpBackend()
 	defer os.RemoveAll(tmpPath)
-	s.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &s.consistIndex)
+	s.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &s.consistIndex, mvcc.StoreConfig{})
 	s.be = be
 
 	s.start()
@@ -1126,7 +1126,7 @@ func TestTriggerSnap(t *testing.T) {
 	}
 	srv.applyV2 = &applierV2store{store: srv.v2store, cluster: srv.cluster}
 
-	srv.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &srv.consistIndex)
+	srv.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &srv.consistIndex, mvcc.StoreConfig{})
 	srv.be = be
 
 	srv.start()
@@ -1198,7 +1198,7 @@ func TestConcurrentApplyAndSnapshotV3(t *testing.T) {
 	defer func() {
 		os.RemoveAll(tmpPath)
 	}()
-	s.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &s.consistIndex)
+	s.kv = mvcc.New(zap.NewExample(), be, &lease.FakeLessor{}, &s.consistIndex, mvcc.StoreConfig{})
 	s.be = be
 
 	s.start()

functional.yaml

@@ -29,7 +29,7 @@ agent-configs:
     initial-cluster: s1=https://127.0.0.1:1381,s2=https://127.0.0.1:2381,s3=https://127.0.0.1:3381
     initial-cluster-state: new
     initial-cluster-token: tkn
-    snapshot-count: 10000
+    snapshot-count: 2000
     quota-backend-bytes: 10740000000 # 10 GiB
     pre-vote: true
     initial-corrupt-check: true
@@ -80,7 +80,7 @@ agent-configs:
     initial-cluster: s1=https://127.0.0.1:1381,s2=https://127.0.0.1:2381,s3=https://127.0.0.1:3381
     initial-cluster-state: new
     initial-cluster-token: tkn
-    snapshot-count: 10000
+    snapshot-count: 2000
     quota-backend-bytes: 10740000000 # 10 GiB
     pre-vote: true
     initial-corrupt-check: true
@@ -131,7 +131,7 @@ agent-configs:
     initial-cluster: s1=https://127.0.0.1:1381,s2=https://127.0.0.1:2381,s3=https://127.0.0.1:3381
     initial-cluster-state: new
     initial-cluster-token: tkn
-    snapshot-count: 10000
+    snapshot-count: 2000
     quota-backend-bytes: 10740000000 # 10 GiB
     pre-vote: true
     initial-corrupt-check: true

functional/Dockerfile

@@ -20,12 +20,12 @@ RUN rm -rf ${GOROOT} \
   && mkdir -p ${GOPATH}/src ${GOPATH}/bin \
   && go version
 
-RUN mkdir -p ${GOPATH}/src/github.com/etcd-io/etcd
-ADD . ${GOPATH}/src/github.com/etcd-io/etcd
+RUN mkdir -p ${GOPATH}/src/go.etcd.io/etcd
+ADD . ${GOPATH}/src/go.etcd.io/etcd
 ADD ./functional.yaml /functional.yaml
 
-RUN go get -v github.com/etcd-io/gofail \
-  && pushd ${GOPATH}/src/github.com/etcd-io/etcd \
+RUN go get -v go.etcd.io/gofail \
+  && pushd ${GOPATH}/src/go.etcd.io/etcd \
   && GO_BUILD_FLAGS="-v" ./build \
   && mkdir -p /bin \
   && cp ./bin/etcd /bin/etcd \
@@ -39,4 +39,4 @@ RUN go get -v github.com/etcd-io/gofail \
   && cp ./bin/etcd-tester /bin/etcd-tester \
   && go build -v -o /bin/benchmark ./tools/benchmark \
   && popd \
-  && rm -rf ${GOPATH}/src/github.com/etcd-io/etcd
+  && rm -rf ${GOPATH}/src/go.etcd.io/etcd

functional/README.md

@@ -24,12 +24,12 @@ And run [example scripts](./scripts).
 
 ```bash
 # run 3 agents for 3-node local etcd cluster
-./scripts/docker-local-agent.sh 1
-./scripts/docker-local-agent.sh 2
-./scripts/docker-local-agent.sh 3
+./functional/scripts/docker-local-agent.sh 1
+./functional/scripts/docker-local-agent.sh 2
+./functional/scripts/docker-local-agent.sh 3
 
 # to run only 1 tester round
-./scripts/docker-local-tester.sh
+./functional/scripts/docker-local-tester.sh
 ```
 
 ## etcd Proxy

functional/agent/handler.go

@@ -25,7 +25,6 @@ import (
 	"syscall"
 	"time"
 
-	"go.etcd.io/etcd/embed"
 	"go.etcd.io/etcd/functional/rpcpb"
 	"go.etcd.io/etcd/pkg/fileutil"
 	"go.etcd.io/etcd/pkg/proxy"
@@ -97,42 +96,26 @@ func (srv *Server) createEtcdLogFile() error {
 }
 
 func (srv *Server) creatEtcd(fromSnapshot bool) error {
-	if !fileutil.Exist(srv.Member.EtcdExec) && srv.Member.EtcdExec != "embed" {
-		return fmt.Errorf("unknown etcd exec %q or path does not exist", srv.Member.EtcdExec)
+	if !fileutil.Exist(srv.Member.EtcdExec) {
+		return fmt.Errorf("unknown etcd exec path %q does not exist", srv.Member.EtcdExec)
 	}
 
-	if srv.Member.EtcdExec != "embed" {
-		etcdPath, etcdFlags := srv.Member.EtcdExec, srv.Member.Etcd.Flags()
-		if fromSnapshot {
-			etcdFlags = srv.Member.EtcdOnSnapshotRestore.Flags()
-		}
-		u, _ := url.Parse(srv.Member.FailpointHTTPAddr)
-		srv.lg.Info(
-			"creating etcd command",
-			zap.String("etcd-exec", etcdPath),
-			zap.Strings("etcd-flags", etcdFlags),
-			zap.String("failpoint-http-addr", srv.Member.FailpointHTTPAddr),
-			zap.String("failpoint-addr", u.Host),
-		)
-		srv.etcdCmd = exec.Command(etcdPath, etcdFlags...)
-		srv.etcdCmd.Env = []string{"GOFAIL_HTTP=" + u.Host}
-		srv.etcdCmd.Stdout = srv.etcdLogFile
-		srv.etcdCmd.Stderr = srv.etcdLogFile
-		return nil
+	etcdPath, etcdFlags := srv.Member.EtcdExec, srv.Member.Etcd.Flags()
+	if fromSnapshot {
+		etcdFlags = srv.Member.EtcdOnSnapshotRestore.Flags()
 	}
-
-	cfg, err := srv.Member.Etcd.EmbedConfig()
-	if err != nil {
-		return err
-	}
-
-	srv.lg.Info("starting embedded etcd", zap.String("name", cfg.Name))
-	srv.etcdServer, err = embed.StartEtcd(cfg)
-	if err != nil {
-		return err
-	}
-	srv.lg.Info("started embedded etcd", zap.String("name", cfg.Name))
-
+	u, _ := url.Parse(srv.Member.FailpointHTTPAddr)
+	srv.lg.Info(
+		"creating etcd command",
+		zap.String("etcd-exec", etcdPath),
+		zap.Strings("etcd-flags", etcdFlags),
+		zap.String("failpoint-http-addr", srv.Member.FailpointHTTPAddr),
+		zap.String("failpoint-addr", u.Host),
+	)
+	srv.etcdCmd = exec.Command(etcdPath, etcdFlags...)
+	srv.etcdCmd.Env = []string{"GOFAIL_HTTP=" + u.Host}
+	srv.etcdCmd.Stdout = srv.etcdLogFile
+	srv.etcdCmd.Stderr = srv.etcdLogFile
 	return nil
 }
 
@@ -399,7 +382,7 @@ func (srv *Server) loadAutoTLSAssets() error {
 		fdir := filepath.Join(srv.Member.Etcd.DataDir, "fixtures", "peer")
 
 		srv.lg.Info(
-			"loading client auto TLS assets",
+			"loading peer auto TLS assets",
 			zap.String("dir", fdir),
 			zap.String("endpoint", srv.EtcdClientEndpoint),
 		)
@@ -467,10 +450,10 @@ func (srv *Server) loadAutoTLSAssets() error {
 
 		srv.lg.Info(
 			"loaded client TLS assets",
-			zap.String("peer-cert-path", certPath),
-			zap.Int("peer-cert-length", len(certData)),
-			zap.String("peer-key-path", keyPath),
-			zap.Int("peer-key-length", len(keyData)),
+			zap.String("client-cert-path", certPath),
+			zap.Int("client-cert-length", len(certData)),
+			zap.String("client-key-path", keyPath),
+			zap.Int("client-key-length", len(keyData)),
 		)
 	}
 

functional/agent/server.go

@@ -126,11 +126,12 @@ func (srv *Server) Stop() {
 }
 
 // Transport communicates with etcd tester.
-func (srv *Server) Transport(stream rpcpb.Transport_TransportServer) (err error) {
-	errc := make(chan error)
+func (srv *Server) Transport(stream rpcpb.Transport_TransportServer) (reterr error) {
+	errc := make(chan error, 1)
 	go func() {
 		for {
 			var req *rpcpb.Request
+			var err error
 			req, err = stream.Recv()
 			if err != nil {
 				errc <- err
@@ -161,9 +162,9 @@ func (srv *Server) Transport(stream rpcpb.Transport_TransportServer) (err error)
 	}()
 
 	select {
-	case err = <-errc:
+	case reterr = <-errc:
 	case <-stream.Context().Done():
-		err = stream.Context().Err()
+		reterr = stream.Context().Err()
 	}
-	return err
+	return reterr
 }

functional/agent/utils.go

@@ -15,6 +15,7 @@
 package agent
 
 import (
+	"io"
 	"net"
 	"net/url"
 	"os"
@@ -36,7 +37,8 @@ func archive(baseDir, etcdLogPath, dataDir string) error {
 		return err
 	}
 
-	if err := os.Rename(etcdLogPath, filepath.Join(dir, "etcd.log")); err != nil {
+	dst := filepath.Join(dir, "etcd.log")
+	if err := copyFile(etcdLogPath, dst); err != nil {
 		if !os.IsNotExist(err) {
 			return err
 		}
@@ -79,6 +81,25 @@ func getURLAndPort(addr string) (urlAddr *url.URL, port int, err error) {
 	return urlAddr, port, err
 }
 
+func copyFile(src, dst string) error {
+	f, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	w, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer w.Close()
+
+	if _, err = io.Copy(w, f); err != nil {
+		return err
+	}
+	return w.Sync()
+}
+
 func cleanPageCache() error {
 	// https://www.kernel.org/doc/Documentation/sysctl/vm.txt
 	// https://github.com/torvalds/linux/blob/master/fs/drop_caches.c

functional/rpcpb/etcd_config.go

@@ -18,10 +18,6 @@ import (
 	"fmt"
 	"reflect"
 	"strings"
-
-	"go.etcd.io/etcd/embed"
-	"go.etcd.io/etcd/pkg/transport"
-	"go.etcd.io/etcd/pkg/types"
 )
 
 var etcdFields = []string{
@@ -105,70 +101,3 @@ func (e *Etcd) Flags() (fs []string) {
 	}
 	return fs
 }
-
-// EmbedConfig returns etcd embed.Config.
-func (e *Etcd) EmbedConfig() (cfg *embed.Config, err error) {
-	var lcURLs types.URLs
-	lcURLs, err = types.NewURLs(e.ListenClientURLs)
-	if err != nil {
-		return nil, err
-	}
-	var acURLs types.URLs
-	acURLs, err = types.NewURLs(e.AdvertiseClientURLs)
-	if err != nil {
-		return nil, err
-	}
-	var lpURLs types.URLs
-	lpURLs, err = types.NewURLs(e.ListenPeerURLs)
-	if err != nil {
-		return nil, err
-	}
-	var apURLs types.URLs
-	apURLs, err = types.NewURLs(e.AdvertisePeerURLs)
-	if err != nil {
-		return nil, err
-	}
-
-	cfg = embed.NewConfig()
-	cfg.Name = e.Name
-	cfg.Dir = e.DataDir
-	cfg.WalDir = e.WALDir
-	cfg.TickMs = uint(e.HeartbeatIntervalMs)
-	cfg.ElectionMs = uint(e.ElectionTimeoutMs)
-
-	cfg.LCUrls = lcURLs
-	cfg.ACUrls = acURLs
-	cfg.ClientAutoTLS = e.ClientAutoTLS
-	cfg.ClientTLSInfo = transport.TLSInfo{
-		ClientCertAuth: e.ClientCertAuth,
-		CertFile:       e.ClientCertFile,
-		KeyFile:        e.ClientKeyFile,
-		TrustedCAFile:  e.ClientTrustedCAFile,
-	}
-
-	cfg.LPUrls = lpURLs
-	cfg.APUrls = apURLs
-	cfg.PeerAutoTLS = e.PeerAutoTLS
-	cfg.PeerTLSInfo = transport.TLSInfo{
-		ClientCertAuth: e.PeerClientCertAuth,
-		CertFile:       e.PeerCertFile,
-		KeyFile:        e.PeerKeyFile,
-		TrustedCAFile:  e.PeerTrustedCAFile,
-	}
-
-	cfg.InitialCluster = e.InitialCluster
-	cfg.ClusterState = e.InitialClusterState
-	cfg.InitialClusterToken = e.InitialClusterToken
-
-	cfg.SnapshotCount = uint64(e.SnapshotCount)
-	cfg.QuotaBackendBytes = e.QuotaBackendBytes
-
-	cfg.PreVote = e.PreVote
-	cfg.ExperimentalInitialCorruptCheck = e.InitialCorruptCheck
-
-	cfg.Logger = e.Logger
-	cfg.LogOutputs = e.LogOutputs
-	cfg.LogLevel = e.LogLevel
-
-	return cfg, nil
-}

functional/rpcpb/etcd_config_test.go

@@ -17,9 +17,6 @@ package rpcpb
 import (
 	"reflect"
 	"testing"
-
-	"go.etcd.io/etcd/embed"
-	"go.etcd.io/etcd/pkg/types"
 )
 
 func TestEtcd(t *testing.T) {
@@ -91,55 +88,4 @@ func TestEtcd(t *testing.T) {
 	if !reflect.DeepEqual(exps, fs) {
 		t.Fatalf("expected %q, got %q", exps, fs)
 	}
-
-	var err error
-	var lcURLs types.URLs
-	lcURLs, err = types.NewURLs([]string{"https://127.0.0.1:1379"})
-	if err != nil {
-		t.Fatal(err)
-	}
-	var acURLs types.URLs
-	acURLs, err = types.NewURLs([]string{"https://127.0.0.1:13790"})
-	if err != nil {
-		t.Fatal(err)
-	}
-	var lpURLs types.URLs
-	lpURLs, err = types.NewURLs([]string{"https://127.0.0.1:1380"})
-	if err != nil {
-		t.Fatal(err)
-	}
-	var apURLs types.URLs
-	apURLs, err = types.NewURLs([]string{"https://127.0.0.1:13800"})
-	if err != nil {
-		t.Fatal(err)
-	}
-	expc := embed.NewConfig()
-	expc.Name = "s1"
-	expc.Dir = "/tmp/etcd-functionl-1/etcd.data"
-	expc.WalDir = "/tmp/etcd-functionl-1/etcd.data/member/wal"
-	expc.TickMs = 100
-	expc.ElectionMs = 1000
-	expc.LCUrls = lcURLs
-	expc.ACUrls = acURLs
-	expc.ClientAutoTLS = true
-	expc.LPUrls = lpURLs
-	expc.APUrls = apURLs
-	expc.PeerAutoTLS = true
-	expc.InitialCluster = "s1=https://127.0.0.1:13800,s2=https://127.0.0.1:23800,s3=https://127.0.0.1:33800"
-	expc.ClusterState = "new"
-	expc.InitialClusterToken = "tkn"
-	expc.SnapshotCount = 10000
-	expc.QuotaBackendBytes = 10740000000
-	expc.PreVote = true
-	expc.ExperimentalInitialCorruptCheck = true
-	expc.Logger = "zap"
-	expc.LogOutputs = []string{"/tmp/etcd-functional-1/etcd.log"}
-	expc.LogLevel = "info"
-	cfg, err := e.EmbedConfig()
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !reflect.DeepEqual(expc, cfg) {
-		t.Fatalf("expected %+v, got %+v", expc, cfg)
-	}
 }

functional/rpcpb/member.go

@@ -25,6 +25,7 @@ import (
 	"go.etcd.io/etcd/clientv3"
 	"go.etcd.io/etcd/clientv3/snapshot"
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/pkg/logutil"
 	"go.etcd.io/etcd/pkg/transport"
 
 	"github.com/dustin/go-humanize"
@@ -94,10 +95,19 @@ func (m *Member) CreateEtcdClientConfig(opts ...grpc.DialOption) (cfg *clientv3.
 		}
 	}
 
+	// TODO: make this configurable
+	level := "error"
+	if os.Getenv("ETCD_CLIENT_DEBUG") != "" {
+		level = "debug"
+	}
+	lcfg := logutil.DefaultZapLoggerConfig
+	lcfg.Level = zap.NewAtomicLevelAt(logutil.ConvertToZapLevel(level))
+
 	cfg = &clientv3.Config{
 		Endpoints:   []string{m.EtcdClientEndpoint},
 		DialTimeout: 10 * time.Second,
 		DialOptions: opts,
+		LogConfig:   &lcfg,
 	}
 	if secure {
 		// assume save TLS assets are already stord on disk

functional/scripts/docker-local-agent.sh

@@ -13,7 +13,7 @@ if ! [[ "${0}" =~ "scripts/docker-local-agent.sh" ]]; then
 fi
 
 if [[ -z "${GO_VERSION}" ]]; then
-  GO_VERSION=1.10.1
+  GO_VERSION=1.12.9
 fi
 echo "Running with GO_VERSION:" ${GO_VERSION}
 
@@ -38,5 +38,5 @@ docker run \
   --rm \
   --net=host \
   --name ${AGENT_NAME} \
-  gcr.io/etcd-development/etcd-functional-tester:go${GO_VERSION} \
+  gcr.io/etcd-development/etcd-functional:go${GO_VERSION} \
   /bin/bash -c "./bin/etcd-agent ${AGENT_ADDR_FLAG}"

functional/scripts/docker-local-tester.sh

@@ -6,7 +6,7 @@ if ! [[ "${0}" =~ "scripts/docker-local-tester.sh" ]]; then
 fi
 
 if [[ -z "${GO_VERSION}" ]]; then
-  GO_VERSION=1.10.1
+  GO_VERSION=1.12.9
 fi
 echo "Running with GO_VERSION:" ${GO_VERSION}
 
@@ -14,5 +14,5 @@ docker run \
   --rm \
   --net=host \
   --name tester \
-  gcr.io/etcd-development/etcd-functional-tester:go${GO_VERSION} \
+  gcr.io/etcd-development/etcd-functional:go${GO_VERSION} \
   /bin/bash -c "./bin/etcd-tester --config ./functional.yaml"

functional/tester/cluster_run.go

@@ -212,8 +212,8 @@ func (clus *Cluster) doRound() error {
 				)
 
 				// with network delay, some ongoing requests may fail
-				// only return error, if more than 10% of QPS requests fail
-				if cnt > int(clus.Tester.StressQPS)/10 {
+				// only return error, if more than 30% of QPS requests fail
+				if cnt > int(float64(clus.Tester.StressQPS)*0.3) {
 					return fmt.Errorf("expected no error in %q, got %q", fcase.String(), ess)
 				}
 			}

functional/tester/stresser_key.go

@@ -176,9 +176,6 @@ func (s *keyStresser) isRetryableError(err error) bool {
 	case context.Canceled.Error():
 		// from stresser.Cancel method:
 		return false
-	case grpc.ErrClientConnClosing.Error():
-		// from stresser.Cancel method:
-		return false
 	}
 
 	if status.Convert(err).Code() == codes.Unavailable {

go.mod

@@ -2,7 +2,7 @@ module go.etcd.io/etcd
 
 require (
 	github.com/bgentry/speakeasy v0.1.0
-	github.com/cockroachdb/datadriven v0.0.0-20190531201743-edce55837238
+	github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa
 	github.com/coreos/go-semver v0.2.0
 	github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7
 	github.com/coreos/pkg v0.0.0-20160727233714-3ac0863d7acf
@@ -40,9 +40,10 @@ require (
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.10.0
 	golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2
-	golang.org/x/net v0.0.0-20190311183353-d8887717615a
+	golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7
+	golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456 // indirect
 	golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2
-	google.golang.org/grpc v1.22.1
+	google.golang.org/grpc v1.23.0
 	gopkg.in/cheggaaa/pb.v1 v1.0.25
 	gopkg.in/yaml.v2 v2.2.2
 	sigs.k8s.io/yaml v1.1.0

go.sum

@@ -9,8 +9,8 @@ github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+Ce
 github.com/bgentry/speakeasy v0.1.0 h1:ByYyxL9InA1OWqxJqqp2A5pYHUrCiAL6K3J+LKSsQkY=
 github.com/bgentry/speakeasy v0.1.0/go.mod h1:+zsyZBPWlz7T6j88CTgSN5bM796AkVf0kBD4zp0CCIs=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
-github.com/cockroachdb/datadriven v0.0.0-20190531201743-edce55837238 h1:uNljlOxtOHrPnRoPPx+JanqjAGZpNiqAGVBfGskd/pg=
-github.com/cockroachdb/datadriven v0.0.0-20190531201743-edce55837238/go.mod h1:zn76sxSg3SzpJ0PPJaLDCu+Bu0Lg3sKTORVIj19EIF8=
+github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa h1:OaNxuTZr7kxeODyLWsRMC+OD03aFUH+mW6r2d+MWa5Y=
+github.com/cockroachdb/datadriven v0.0.0-20190809214429-80d97fb3cbaa/go.mod h1:zn76sxSg3SzpJ0PPJaLDCu+Bu0Lg3sKTORVIj19EIF8=
 github.com/coreos/go-semver v0.2.0 h1:3Jm3tLmsgAYcjC+4Up7hJrFBPr+n7rAqYeSw/SZazuY=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-systemd v0.0.0-20180511133405-39ca1b05acc7 h1:u9SHYsPQNyt5tgDm3YN7+9dYrpK96E5wFilTFWIDZOM=
@@ -153,6 +153,8 @@ golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73r
 golang.org/x/net v0.0.0-20181220203305-927f97764cc3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7 h1:fHDIZ2oxGnUZRN6WgWFCbYBjH9uqVPRCUVUDhs0wnbA=
+golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -165,6 +167,8 @@ golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5 h1:mzjBh+S5frKOsOBobWIMAbXav
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456 h1:ng0gs1AKnRRuEMZoTLLlbOd+C17zUDepwGQBb/n+JVg=
+golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/time v0.0.0-20180412165947-fbb02b2291d2 h1:+DCIGbF/swA92ohVg0//6X2IVY3KZs6p9mix0ziNYJM=
@@ -177,8 +181,8 @@ google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9Ywl
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8 h1:Nw54tB0rB7hY/N0NQvRW8DG4Yk3Q6T9cu9RcFQDu1tc=
 google.golang.org/genproto v0.0.0-20180817151627-c66870c02cf8/go.mod h1:JiN7NxoALGmiZfu7CAH4rXhgtRTLTxftemlI0sWmxmc=
 google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZiDr8c=
-google.golang.org/grpc v1.22.1 h1:/7cs52RnTJmD43s3uxzlq2U7nqVTd/37viQwMrMNlOM=
-google.golang.org/grpc v1.22.1/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
+google.golang.org/grpc v1.23.0 h1:AzbTB6ux+okLTzP8Ru1Xs41C303zdcfEht7MQnYJt5A=
+google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

integration/metrics_test.go

@@ -206,11 +206,11 @@ func TestMetricsHealth(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	hv, err := clus.Members[0].Metric("etcd_server_health_failure")
+	hv, err := clus.Members[0].Metric("etcd_server_health_failures")
 	if err != nil {
 		t.Fatal(err)
 	}
 	if hv != "0" {
-		t.Fatalf("expected '0' from etcd_server_health_failure, got %q", hv)
+		t.Fatalf("expected '0' from etcd_server_health_failures, got %q", hv)
 	}
 }

integration/v3_alarm_test.go

@@ -169,7 +169,7 @@ func TestV3CorruptAlarm(t *testing.T) {
 	clus.Members[0].Stop(t)
 	fp := filepath.Join(clus.Members[0].DataDir, "member", "snap", "db")
 	be := backend.NewDefaultBackend(fp)
-	s := mvcc.NewStore(zap.NewExample(), be, nil, &fakeConsistentIndex{13})
+	s := mvcc.NewStore(zap.NewExample(), be, nil, &fakeConsistentIndex{13}, mvcc.StoreConfig{})
 	// NOTE: cluster_proxy mode with namespacing won't set 'k', but namespace/'k'.
 	s.Put([]byte("abc"), []byte("def"), 0)
 	s.Put([]byte("xyz"), []byte("123"), 0)

integration/v3_watch_restore_test.go

@@ -71,7 +71,25 @@ func TestV3WatchRestoreSnapshotUnsync(t *testing.T) {
 	// trigger snapshot send from leader to this slow follower
 	// which then calls watchable store Restore
 	clus.Members[0].RecoverPartition(t, clus.Members[1:]...)
-	clus.WaitLeader(t)
+	lead := clus.WaitLeader(t)
+
+	sends, err := clus.Members[lead].Metric("etcd_network_snapshot_send_inflights_total")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sends != "0" && sends != "1" {
+		// 0 if already sent, 1 if sending
+		t.Fatalf("inflight snapshot sends expected 0 or 1, got %q", sends)
+	}
+	receives, err := clus.Members[(lead+1)%3].Metric("etcd_network_snapshot_receive_inflights_total")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if receives != "0" && receives != "1" {
+		// 0 if already received, 1 if receiving
+		t.Fatalf("inflight snapshot receives expected 0 or 1, got %q", receives)
+	}
+
 	time.Sleep(2 * time.Second)
 
 	// slow follower now applies leader snapshot

mvcc/kv_test.go

@@ -76,7 +76,7 @@ func TestKVTxnRange(t *testing.T) { testKVRange(t, txnRangeFunc) }
 
 func testKVRange(t *testing.T, f rangeFunc) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	kvs := put3TestKVs(s)
@@ -142,7 +142,7 @@ func TestKVTxnRangeRev(t *testing.T) { testKVRangeRev(t, txnRangeFunc) }
 
 func testKVRangeRev(t *testing.T, f rangeFunc) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	kvs := put3TestKVs(s)
@@ -178,7 +178,7 @@ func TestKVTxnRangeBadRev(t *testing.T) { testKVRangeBadRev(t, txnRangeFunc) }
 
 func testKVRangeBadRev(t *testing.T, f rangeFunc) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	put3TestKVs(s)
@@ -211,7 +211,7 @@ func TestKVTxnRangeLimit(t *testing.T) { testKVRangeLimit(t, txnRangeFunc) }
 
 func testKVRangeLimit(t *testing.T, f rangeFunc) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	kvs := put3TestKVs(s)
@@ -252,7 +252,7 @@ func TestKVTxnPutMultipleTimes(t *testing.T) { testKVPutMultipleTimes(t, txnPutF
 
 func testKVPutMultipleTimes(t *testing.T, f putFunc) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	for i := 0; i < 10; i++ {
@@ -314,7 +314,7 @@ func testKVDeleteRange(t *testing.T, f deleteRangeFunc) {
 
 	for i, tt := range tests {
 		b, tmpPath := backend.NewDefaultTmpBackend()
-		s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+		s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 		s.Put([]byte("foo"), []byte("bar"), lease.NoLease)
 		s.Put([]byte("foo1"), []byte("bar1"), lease.NoLease)
@@ -334,7 +334,7 @@ func TestKVTxnDeleteMultipleTimes(t *testing.T) { testKVDeleteMultipleTimes(t, t
 
 func testKVDeleteMultipleTimes(t *testing.T, f deleteRangeFunc) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	s.Put([]byte("foo"), []byte("bar"), lease.NoLease)
@@ -355,7 +355,7 @@ func testKVDeleteMultipleTimes(t *testing.T, f deleteRangeFunc) {
 // test that range, put, delete on single key in sequence repeatedly works correctly.
 func TestKVOperationInSequence(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	for i := 0; i < 10; i++ {
@@ -402,7 +402,7 @@ func TestKVOperationInSequence(t *testing.T) {
 
 func TestKVTxnBlockWriteOperations(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	tests := []func(){
 		func() { s.Put([]byte("foo"), nil, lease.NoLease) },
@@ -435,7 +435,7 @@ func TestKVTxnBlockWriteOperations(t *testing.T) {
 
 func TestKVTxnNonBlockRange(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	txn := s.Write()
@@ -456,7 +456,7 @@ func TestKVTxnNonBlockRange(t *testing.T) {
 // test that txn range, put, delete on single key in sequence repeatedly works correctly.
 func TestKVTxnOperationInSequence(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	for i := 0; i < 10; i++ {
@@ -506,7 +506,7 @@ func TestKVTxnOperationInSequence(t *testing.T) {
 
 func TestKVCompactReserveLastValue(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	s.Put([]byte("foo"), []byte("bar0"), 1)
@@ -560,7 +560,7 @@ func TestKVCompactReserveLastValue(t *testing.T) {
 
 func TestKVCompactBad(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	s.Put([]byte("foo"), []byte("bar0"), lease.NoLease)
@@ -593,7 +593,7 @@ func TestKVHash(t *testing.T) {
 	for i := 0; i < len(hashes); i++ {
 		var err error
 		b, tmpPath := backend.NewDefaultTmpBackend()
-		kv := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+		kv := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 		kv.Put([]byte("foo0"), []byte("bar0"), lease.NoLease)
 		kv.Put([]byte("foo1"), []byte("bar0"), lease.NoLease)
 		hashes[i], _, err = kv.Hash()
@@ -631,7 +631,7 @@ func TestKVRestore(t *testing.T) {
 	}
 	for i, tt := range tests {
 		b, tmpPath := backend.NewDefaultTmpBackend()
-		s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+		s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 		tt(s)
 		var kvss [][]mvccpb.KeyValue
 		for k := int64(0); k < 10; k++ {
@@ -643,7 +643,7 @@ func TestKVRestore(t *testing.T) {
 		s.Close()
 
 		// ns should recover the the previous state from backend.
-		ns := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+		ns := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 		if keysRestore := readGaugeInt(keysGauge); keysBefore != keysRestore {
 			t.Errorf("#%d: got %d key count, expected %d", i, keysRestore, keysBefore)
@@ -675,7 +675,7 @@ func readGaugeInt(g prometheus.Gauge) int {
 
 func TestKVSnapshot(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	wkvs := put3TestKVs(s)
@@ -695,7 +695,7 @@ func TestKVSnapshot(t *testing.T) {
 	}
 	f.Close()
 
-	ns := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	ns := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer ns.Close()
 	r, err := ns.Range([]byte("a"), []byte("z"), RangeOptions{})
 	if err != nil {
@@ -711,7 +711,7 @@ func TestKVSnapshot(t *testing.T) {
 
 func TestWatchableKVWatch(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()

mvcc/kvstore.go

@@ -60,6 +60,7 @@ const (
 )
 
 var restoreChunkKeys = 10000 // non-const for testing
+var defaultCompactBatchLimit = 1000
 
 // ConsistentIndexGetter is an interface that wraps the Get method.
 // Consistent index is the offset of an entry in a consistent replicated log.
@@ -68,6 +69,10 @@ type ConsistentIndexGetter interface {
 	ConsistentIndex() uint64
 }
 
+type StoreConfig struct {
+	CompactionBatchLimit int
+}
+
 type store struct {
 	ReadView
 	WriteView
@@ -76,6 +81,8 @@ type store struct {
 	// through atomics so must be 64-bit aligned.
 	consistentIndex uint64
 
+	cfg StoreConfig
+
 	// mu read locks for txns and write locks for non-txn store changes.
 	mu sync.RWMutex
 
@@ -108,8 +115,12 @@ type store struct {
 
 // NewStore returns a new store. It is useful to create a store inside
 // mvcc pkg. It should only be used for testing externally.
-func NewStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter) *store {
+func NewStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter, cfg StoreConfig) *store {
+	if cfg.CompactionBatchLimit == 0 {
+		cfg.CompactionBatchLimit = defaultCompactBatchLimit
+	}
 	s := &store{
+		cfg:     cfg,
 		b:       b,
 		ig:      ig,
 		kvindex: newTreeIndex(lg),

mvcc/kvstore_bench_test.go

@@ -33,7 +33,7 @@ func (i *fakeConsistentIndex) ConsistentIndex() uint64 {
 func BenchmarkStorePut(b *testing.B) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	// arbitrary number of bytes
@@ -53,7 +53,7 @@ func BenchmarkStoreRangeKey100(b *testing.B) { benchmarkStoreRange(b, 100) }
 func benchmarkStoreRange(b *testing.B, n int) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	// 64 byte key/val
@@ -81,7 +81,7 @@ func benchmarkStoreRange(b *testing.B, n int) {
 func BenchmarkConsistentIndex(b *testing.B) {
 	fci := fakeConsistentIndex(10)
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &fci)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &fci, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	tx := s.b.BatchTx()
@@ -100,7 +100,7 @@ func BenchmarkConsistentIndex(b *testing.B) {
 func BenchmarkStorePutUpdate(b *testing.B) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	// arbitrary number of bytes
@@ -119,7 +119,7 @@ func BenchmarkStorePutUpdate(b *testing.B) {
 func BenchmarkStoreTxnPut(b *testing.B) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	// arbitrary number of bytes
@@ -140,7 +140,7 @@ func BenchmarkStoreTxnPut(b *testing.B) {
 func benchmarkStoreRestore(revsPerKey int, b *testing.B) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 	// use closure to capture 's' to pick up the reassignment
 	defer func() { cleanup(s, be, tmpPath) }()
 
@@ -160,7 +160,7 @@ func benchmarkStoreRestore(revsPerKey int, b *testing.B) {
 
 	b.ReportAllocs()
 	b.ResetTimer()
-	s = NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s = NewStore(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 }
 
 func BenchmarkStoreRestoreRevs1(b *testing.B) {

mvcc/kvstore_compaction.go

@@ -30,25 +30,23 @@ func (s *store) scheduleCompaction(compactMainRev int64, keep map[revision]struc
 	end := make([]byte, 8)
 	binary.BigEndian.PutUint64(end, uint64(compactMainRev+1))
 
-	batchsize := int64(10000)
 	last := make([]byte, 8+1+8)
 	for {
 		var rev revision
 
 		start := time.Now()
+
 		tx := s.b.BatchTx()
 		tx.Lock()
-
-		keys, _ := tx.UnsafeRange(keyBucketName, last, end, batchsize)
+		keys, _ := tx.UnsafeRange(keyBucketName, last, end, int64(s.cfg.CompactionBatchLimit))
 		for _, key := range keys {
 			rev = bytesToRev(key)
 			if _, ok := keep[rev]; !ok {
 				tx.UnsafeDelete(keyBucketName, key)
-				keyCompactions++
 			}
 		}
 
-		if len(keys) < int(batchsize) {
+		if len(keys) < s.cfg.CompactionBatchLimit {
 			rbytes := make([]byte, 8+1+8)
 			revToBytes(revision{main: compactMainRev}, rbytes)
 			tx.UnsafePut(metaBucketName, finishedCompactKeyName, rbytes)
@@ -60,7 +58,7 @@ func (s *store) scheduleCompaction(compactMainRev int64, keep map[revision]struc
 					zap.Duration("took", time.Since(totalStart)),
 				)
 			} else {
-				plog.Printf("finished scheduled compaction at %d (took %v)", compactMainRev, time.Since(totalStart))
+				plog.Infof("finished scheduled compaction at %d (took %v)", compactMainRev, time.Since(totalStart))
 			}
 			return true
 		}
@@ -68,10 +66,12 @@ func (s *store) scheduleCompaction(compactMainRev int64, keep map[revision]struc
 		// update last
 		revToBytes(revision{main: rev.main, sub: rev.sub + 1}, last)
 		tx.Unlock()
+		// Immediately commit the compaction deletes instead of letting them accumulate in the write buffer
+		s.b.ForceCommit()
 		dbCompactionPauseMs.Observe(float64(time.Since(start) / time.Millisecond))
 
 		select {
-		case <-time.After(100 * time.Millisecond):
+		case <-time.After(10 * time.Millisecond):
 		case <-s.stopc:
 			return false
 		}

mvcc/kvstore_compaction_test.go

@@ -65,7 +65,7 @@ func TestScheduleCompaction(t *testing.T) {
 	}
 	for i, tt := range tests {
 		b, tmpPath := backend.NewDefaultTmpBackend()
-		s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+		s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 		tx := s.b.BatchTx()
 
 		tx.Lock()
@@ -99,7 +99,7 @@ func TestScheduleCompaction(t *testing.T) {
 
 func TestCompactAllAndRestore(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s0 := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s0 := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer os.Remove(tmpPath)
 
 	s0.Put([]byte("foo"), []byte("bar"), lease.NoLease)
@@ -125,7 +125,7 @@ func TestCompactAllAndRestore(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	s1 := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s1 := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	if s1.Rev() != rev {
 		t.Errorf("rev = %v, want %v", s1.Rev(), rev)
 	}

mvcc/kvstore_test.go

@@ -40,7 +40,7 @@ import (
 
 func TestStoreRev(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer s.Close()
 	defer os.Remove(tmpPath)
 
@@ -390,7 +390,7 @@ func TestStoreRestore(t *testing.T) {
 	s.restore()
 
 	if s.compactMainRev != 3 {
-		t.Errorf("compact rev = %d, want 5", s.compactMainRev)
+		t.Errorf("compact rev = %d, want 3", s.compactMainRev)
 	}
 	if s.currentRev != 5 {
 		t.Errorf("current rev = %v, want 5", s.currentRev)
@@ -424,7 +424,7 @@ func TestRestoreDelete(t *testing.T) {
 	defer func() { restoreChunkKeys = oldChunk }()
 
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer os.Remove(tmpPath)
 
 	keys := make(map[string]struct{})
@@ -450,7 +450,7 @@ func TestRestoreDelete(t *testing.T) {
 	}
 	s.Close()
 
-	s = NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s = NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer s.Close()
 	for i := 0; i < 20; i++ {
 		ks := fmt.Sprintf("foo-%d", i)
@@ -472,7 +472,7 @@ func TestRestoreContinueUnfinishedCompaction(t *testing.T) {
 	tests := []string{"recreate", "restore"}
 	for _, test := range tests {
 		b, tmpPath := backend.NewDefaultTmpBackend()
-		s0 := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+		s0 := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 		defer os.Remove(tmpPath)
 
 		s0.Put([]byte("foo"), []byte("bar"), lease.NoLease)
@@ -492,7 +492,7 @@ func TestRestoreContinueUnfinishedCompaction(t *testing.T) {
 		var s *store
 		switch test {
 		case "recreate":
-			s = NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+			s = NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 		case "restore":
 			s0.Restore(b)
 			s = s0
@@ -534,7 +534,7 @@ type hashKVResult struct {
 // TestHashKVWhenCompacting ensures that HashKV returns correct hash when compacting.
 func TestHashKVWhenCompacting(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer os.Remove(tmpPath)
 
 	rev := 10000
@@ -602,10 +602,10 @@ func TestHashKVWhenCompacting(t *testing.T) {
 // correct hash value with latest revision.
 func TestHashKVZeroRevision(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer os.Remove(tmpPath)
 
-	rev := 1000
+	rev := 10000
 	for i := 2; i <= rev; i++ {
 		s.Put([]byte("foo"), []byte(fmt.Sprintf("bar%d", i)), lease.NoLease)
 	}
@@ -635,7 +635,7 @@ func TestTxnPut(t *testing.T) {
 	vals := createBytesSlice(bytesN, sliceN)
 
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, b, tmpPath)
 
 	for i := 0; i < sliceN; i++ {
@@ -651,7 +651,7 @@ func TestTxnPut(t *testing.T) {
 // TestConcurrentReadNotBlockingWrite ensures Read does not blocking Write after its creation
 func TestConcurrentReadNotBlockingWrite(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer os.Remove(tmpPath)
 
 	// write something to read later
@@ -720,7 +720,7 @@ func TestConcurrentReadTxAndWrite(t *testing.T) {
 		mu                   sync.Mutex // mu protectes committedKVs
 	)
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer os.Remove(tmpPath)
 
 	var wg sync.WaitGroup
@@ -846,6 +846,7 @@ func newFakeStore() *store {
 		indexCompactRespc:     make(chan map[revision]struct{}, 1),
 	}
 	s := &store{
+		cfg:            StoreConfig{CompactionBatchLimit: 10000},
 		b:              b,
 		le:             &lease.FakeLessor{},
 		kvindex:        fi,

mvcc/watchable_store.go

@@ -68,13 +68,13 @@ type watchableStore struct {
 // cancel operations.
 type cancelFunc func()
 
-func New(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter) ConsistentWatchableKV {
-	return newWatchableStore(lg, b, le, ig)
+func New(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter, cfg StoreConfig) ConsistentWatchableKV {
+	return newWatchableStore(lg, b, le, ig, cfg)
 }
 
-func newWatchableStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter) *watchableStore {
+func newWatchableStore(lg *zap.Logger, b backend.Backend, le lease.Lessor, ig ConsistentIndexGetter, cfg StoreConfig) *watchableStore {
 	s := &watchableStore{
-		store:    NewStore(lg, b, le, ig),
+		store:    NewStore(lg, b, le, ig, cfg),
 		victimc:  make(chan struct{}, 1),
 		unsynced: newWatcherGroup(),
 		synced:   newWatcherGroup(),

mvcc/watchable_store_bench_test.go

@@ -27,7 +27,7 @@ import (
 
 func BenchmarkWatchableStorePut(b *testing.B) {
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := New(zap.NewExample(), be, &lease.FakeLessor{}, nil)
+	s := New(zap.NewExample(), be, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	// arbitrary number of bytes
@@ -48,7 +48,7 @@ func BenchmarkWatchableStorePut(b *testing.B) {
 func BenchmarkWatchableStoreTxnPut(b *testing.B) {
 	var i fakeConsistentIndex
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := New(zap.NewExample(), be, &lease.FakeLessor{}, &i)
+	s := New(zap.NewExample(), be, &lease.FakeLessor{}, &i, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	// arbitrary number of bytes
@@ -79,7 +79,7 @@ func BenchmarkWatchableStoreWatchPutUnsync(b *testing.B) {
 
 func benchmarkWatchableStoreWatchPut(b *testing.B, synced bool) {
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), be, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), be, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s, be, tmpPath)
 
 	k := []byte("testkey")
@@ -122,7 +122,7 @@ func benchmarkWatchableStoreWatchPut(b *testing.B, synced bool) {
 // we should put to simulate the real-world use cases.
 func BenchmarkWatchableStoreUnsyncedCancel(b *testing.B) {
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, nil)
+	s := NewStore(zap.NewExample(), be, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	// manually create watchableStore instead of newWatchableStore
 	// because newWatchableStore periodically calls syncWatchersLoop
@@ -179,7 +179,7 @@ func BenchmarkWatchableStoreUnsyncedCancel(b *testing.B) {
 
 func BenchmarkWatchableStoreSyncedCancel(b *testing.B) {
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), be, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), be, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()

mvcc/watchable_store_test.go

@@ -31,7 +31,7 @@ import (
 
 func TestWatch(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()
@@ -53,7 +53,7 @@ func TestWatch(t *testing.T) {
 
 func TestNewWatcherCancel(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()
@@ -85,7 +85,7 @@ func TestCancelUnsynced(t *testing.T) {
 	// method to sync watchers in unsynced map. We want to keep watchers
 	// in unsynced to test if syncWatchers works as expected.
 	s := &watchableStore{
-		store:    NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil),
+		store:    NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}),
 		unsynced: newWatcherGroup(),
 
 		// to make the test not crash from assigning to nil map.
@@ -140,7 +140,7 @@ func TestSyncWatchers(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
 
 	s := &watchableStore{
-		store:    NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil),
+		store:    NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}),
 		unsynced: newWatcherGroup(),
 		synced:   newWatcherGroup(),
 	}
@@ -223,7 +223,7 @@ func TestSyncWatchers(t *testing.T) {
 // TestWatchCompacted tests a watcher that watches on a compacted revision.
 func TestWatchCompacted(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()
@@ -260,7 +260,7 @@ func TestWatchCompacted(t *testing.T) {
 
 func TestWatchFutureRev(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()
@@ -301,7 +301,7 @@ func TestWatchRestore(t *testing.T) {
 	test := func(delay time.Duration) func(t *testing.T) {
 		return func(t *testing.T) {
 			b, tmpPath := backend.NewDefaultTmpBackend()
-			s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+			s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 			defer cleanup(s, b, tmpPath)
 
 			testKey := []byte("foo")
@@ -309,7 +309,7 @@ func TestWatchRestore(t *testing.T) {
 			rev := s.Put(testKey, testValue, lease.NoLease)
 
 			newBackend, newPath := backend.NewDefaultTmpBackend()
-			newStore := newWatchableStore(zap.NewExample(), newBackend, &lease.FakeLessor{}, nil)
+			newStore := newWatchableStore(zap.NewExample(), newBackend, &lease.FakeLessor{}, nil, StoreConfig{})
 			defer cleanup(newStore, newBackend, newPath)
 
 			w := newStore.NewWatchStream()
@@ -347,11 +347,11 @@ func TestWatchRestore(t *testing.T) {
 //   5. choose the watcher from step 1, without panic
 func TestWatchRestoreSyncedWatcher(t *testing.T) {
 	b1, b1Path := backend.NewDefaultTmpBackend()
-	s1 := newWatchableStore(zap.NewExample(), b1, &lease.FakeLessor{}, nil)
+	s1 := newWatchableStore(zap.NewExample(), b1, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s1, b1, b1Path)
 
 	b2, b2Path := backend.NewDefaultTmpBackend()
-	s2 := newWatchableStore(zap.NewExample(), b2, &lease.FakeLessor{}, nil)
+	s2 := newWatchableStore(zap.NewExample(), b2, &lease.FakeLessor{}, nil, StoreConfig{})
 	defer cleanup(s2, b2, b2Path)
 
 	testKey, testValue := []byte("foo"), []byte("bar")
@@ -398,7 +398,7 @@ func TestWatchRestoreSyncedWatcher(t *testing.T) {
 // TestWatchBatchUnsynced tests batching on unsynced watchers
 func TestWatchBatchUnsynced(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	oldMaxRevs := watchBatchMaxRevs
 	defer func() {
@@ -532,7 +532,7 @@ func TestWatchVictims(t *testing.T) {
 	oldChanBufLen, oldMaxWatchersPerSync := chanBufLen, maxWatchersPerSync
 
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()
@@ -610,7 +610,7 @@ func TestWatchVictims(t *testing.T) {
 // canceling its watches.
 func TestStressWatchCancelClose(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()

mvcc/watcher_bench_test.go

@@ -26,7 +26,7 @@ import (
 
 func BenchmarkKVWatcherMemoryUsage(b *testing.B) {
 	be, tmpPath := backend.NewDefaultTmpBackend()
-	watchable := newWatchableStore(zap.NewExample(), be, &lease.FakeLessor{}, nil)
+	watchable := newWatchableStore(zap.NewExample(), be, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer cleanup(watchable, be, tmpPath)
 

mvcc/watcher_test.go

@@ -32,7 +32,7 @@ import (
 // and the watched event attaches the correct watchID.
 func TestWatcherWatchID(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()
@@ -82,7 +82,7 @@ func TestWatcherWatchID(t *testing.T) {
 
 func TestWatcherRequestsCustomID(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()
@@ -119,7 +119,7 @@ func TestWatcherRequestsCustomID(t *testing.T) {
 // and returns events with matching prefixes.
 func TestWatcherWatchPrefix(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()
@@ -193,7 +193,7 @@ func TestWatcherWatchPrefix(t *testing.T) {
 // does not create watcher, which panics when canceling in range tree.
 func TestWatcherWatchWrongRange(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()
@@ -213,7 +213,7 @@ func TestWatcherWatchWrongRange(t *testing.T) {
 
 func TestWatchDeleteRange(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil)
+	s := newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{})
 
 	defer func() {
 		s.store.Close()
@@ -252,7 +252,7 @@ func TestWatchDeleteRange(t *testing.T) {
 // with given id inside watchStream.
 func TestWatchStreamCancelWatcherByID(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()
@@ -295,7 +295,7 @@ func TestWatcherRequestProgress(t *testing.T) {
 	// method to sync watchers in unsynced map. We want to keep watchers
 	// in unsynced to test if syncWatchers works as expected.
 	s := &watchableStore{
-		store:    NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil),
+		store:    NewStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}),
 		unsynced: newWatcherGroup(),
 		synced:   newWatcherGroup(),
 	}
@@ -344,7 +344,7 @@ func TestWatcherRequestProgress(t *testing.T) {
 
 func TestWatcherWatchWithFilter(t *testing.T) {
 	b, tmpPath := backend.NewDefaultTmpBackend()
-	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil))
+	s := WatchableKV(newWatchableStore(zap.NewExample(), b, &lease.FakeLessor{}, nil, StoreConfig{}))
 	defer cleanup(s, b, tmpPath)
 
 	w := s.NewWatchStream()

pkg/adt/interval_tree.go

@@ -87,39 +87,39 @@ type intervalNode struct {
 	c      rbcolor
 }
 
-func (x *intervalNode) color() rbcolor {
-	if x == nil {
+func (x *intervalNode) color(sentinel *intervalNode) rbcolor {
+	if x == sentinel {
 		return black
 	}
 	return x.c
 }
 
-func (x *intervalNode) height() int {
-	if x == nil {
+func (x *intervalNode) height(sentinel *intervalNode) int {
+	if x == sentinel {
 		return 0
 	}
-	ld := x.left.height()
-	rd := x.right.height()
+	ld := x.left.height(sentinel)
+	rd := x.right.height(sentinel)
 	if ld < rd {
 		return rd + 1
 	}
 	return ld + 1
 }
 
-func (x *intervalNode) min() *intervalNode {
-	for x.left != nil {
+func (x *intervalNode) min(sentinel *intervalNode) *intervalNode {
+	for x.left != sentinel {
 		x = x.left
 	}
 	return x
 }
 
 // successor is the next in-order node in the tree
-func (x *intervalNode) successor() *intervalNode {
-	if x.right != nil {
-		return x.right.min()
+func (x *intervalNode) successor(sentinel *intervalNode) *intervalNode {
+	if x.right != sentinel {
+		return x.right.min(sentinel)
 	}
 	y := x.parent
-	for y != nil && x == y.right {
+	for y != sentinel && x == y.right {
 		x = y
 		y = y.parent
 	}
@@ -127,14 +127,14 @@ func (x *intervalNode) successor() *intervalNode {
 }
 
 // updateMax updates the maximum values for a node and its ancestors
-func (x *intervalNode) updateMax() {
-	for x != nil {
+func (x *intervalNode) updateMax(sentinel *intervalNode) {
+	for x != sentinel {
 		oldmax := x.max
 		max := x.iv.Ivl.End
-		if x.left != nil && x.left.max.Compare(max) > 0 {
+		if x.left != sentinel && x.left.max.Compare(max) > 0 {
 			max = x.left.max
 		}
-		if x.right != nil && x.right.max.Compare(max) > 0 {
+		if x.right != sentinel && x.right.max.Compare(max) > 0 {
 			max = x.right.max
 		}
 		if oldmax.Compare(max) == 0 {
@@ -148,25 +148,25 @@ func (x *intervalNode) updateMax() {
 type nodeVisitor func(n *intervalNode) bool
 
 // visit will call a node visitor on each node that overlaps the given interval
-func (x *intervalNode) visit(iv *Interval, nv nodeVisitor) bool {
-	if x == nil {
+func (x *intervalNode) visit(iv *Interval, sentinel *intervalNode, nv nodeVisitor) bool {
+	if x == sentinel {
 		return true
 	}
 	v := iv.Compare(&x.iv.Ivl)
 	switch {
 	case v < 0:
-		if !x.left.visit(iv, nv) {
+		if !x.left.visit(iv, sentinel, nv) {
 			return false
 		}
 	case v > 0:
 		maxiv := Interval{x.iv.Ivl.Begin, x.max}
 		if maxiv.Compare(iv) == 0 {
-			if !x.left.visit(iv, nv) || !x.right.visit(iv, nv) {
+			if !x.left.visit(iv, sentinel, nv) || !x.right.visit(iv, sentinel, nv) {
 				return false
 			}
 		}
 	default:
-		if !x.left.visit(iv, nv) || !nv(x) || !x.right.visit(iv, nv) {
+		if !x.left.visit(iv, sentinel, nv) || !nv(x) || !x.right.visit(iv, sentinel, nv) {
 			return false
 		}
 	}
@@ -211,9 +211,18 @@ type IntervalTree interface {
 
 // NewIntervalTree returns a new interval tree.
 func NewIntervalTree() IntervalTree {
+	sentinel := &intervalNode{
+		iv:     IntervalValue{},
+		max:    nil,
+		left:   nil,
+		right:  nil,
+		parent: nil,
+		c:      black,
+	}
 	return &intervalTree{
-		root:  nil,
-		count: 0,
+		root:     sentinel,
+		count:    0,
+		sentinel: sentinel,
 	}
 }
 
@@ -221,9 +230,11 @@ type intervalTree struct {
 	root  *intervalNode
 	count int
 
-	// TODO: use 'sentinel' as a dummy object to simplify boundary conditions
+	// red-black NIL node
+	// use 'sentinel' as a dummy object to simplify boundary conditions
 	// use the sentinel to treat a nil child of a node x as an ordinary node whose parent is x
 	// use one shared sentinel to represent all nil leaves and the root's parent
+	sentinel *intervalNode
 }
 
 // TODO: make this consistent with textbook implementation
@@ -263,24 +274,25 @@ type intervalTree struct {
 // true if a node is in fact removed.
 func (ivt *intervalTree) Delete(ivl Interval) bool {
 	z := ivt.find(ivl)
-	if z == nil {
+	if z == ivt.sentinel {
 		return false
 	}
 
 	y := z
-	if z.left != nil && z.right != nil {
-		y = z.successor()
+	if z.left != ivt.sentinel && z.right != ivt.sentinel {
+		y = z.successor(ivt.sentinel)
 	}
 
-	x := y.left
-	if x == nil {
+	x := ivt.sentinel
+	if y.left != ivt.sentinel {
+		x = y.left
+	} else if y.right != ivt.sentinel {
 		x = y.right
 	}
-	if x != nil {
-		x.parent = y.parent
-	}
 
-	if y.parent == nil {
+	x.parent = y.parent
+
+	if y.parent == ivt.sentinel {
 		ivt.root = x
 	} else {
 		if y == y.parent.left {
@@ -288,14 +300,14 @@ func (ivt *intervalTree) Delete(ivl Interval) bool {
 		} else {
 			y.parent.right = x
 		}
-		y.parent.updateMax()
+		y.parent.updateMax(ivt.sentinel)
 	}
 	if y != z {
 		z.iv = y.iv
-		z.updateMax()
+		z.updateMax(ivt.sentinel)
 	}
 
-	if y.color() == black && x != nil {
+	if y.color(ivt.sentinel) == black {
 		ivt.deleteFixup(x)
 	}
 
@@ -348,10 +360,10 @@ func (ivt *intervalTree) Delete(ivl Interval) bool {
 //	40. x.color = BLACK
 //
 func (ivt *intervalTree) deleteFixup(x *intervalNode) {
-	for x != ivt.root && x.color() == black && x.parent != nil {
+	for x != ivt.root && x.color(ivt.sentinel) == black {
 		if x == x.parent.left { // line 3-20
 			w := x.parent.right
-			if w.color() == red {
+			if w.color(ivt.sentinel) == red {
 				w.c = black
 				x.parent.c = red
 				ivt.rotateLeft(x.parent)
@@ -360,28 +372,26 @@ func (ivt *intervalTree) deleteFixup(x *intervalNode) {
 			if w == nil {
 				break
 			}
-			if w.left.color() == black && w.right.color() == black {
+			if w.left.color(ivt.sentinel) == black && w.right.color(ivt.sentinel) == black {
 				w.c = red
 				x = x.parent
 			} else {
-				if w.right.color() == black {
+				if w.right.color(ivt.sentinel) == black {
 					w.left.c = black
 					w.c = red
 					ivt.rotateRight(w)
 					w = x.parent.right
 				}
-				w.c = x.parent.color()
+				w.c = x.parent.color(ivt.sentinel)
 				x.parent.c = black
 				w.right.c = black
 				ivt.rotateLeft(x.parent)
 				x = ivt.root
 			}
-
 		} else { // line 22-38
-
 			// same as above but with left and right exchanged
 			w := x.parent.left
-			if w.color() == red {
+			if w.color(ivt.sentinel) == red {
 				w.c = black
 				x.parent.c = red
 				ivt.rotateRight(x.parent)
@@ -390,17 +400,17 @@ func (ivt *intervalTree) deleteFixup(x *intervalNode) {
 			if w == nil {
 				break
 			}
-			if w.left.color() == black && w.right.color() == black {
+			if w.left.color(ivt.sentinel) == black && w.right.color(ivt.sentinel) == black {
 				w.c = red
 				x = x.parent
 			} else {
-				if w.left.color() == black {
+				if w.left.color(ivt.sentinel) == black {
 					w.right.c = black
 					w.c = red
 					ivt.rotateLeft(w)
 					w = x.parent.left
 				}
-				w.c = x.parent.color()
+				w.c = x.parent.color(ivt.sentinel)
 				x.parent.c = black
 				w.left.c = black
 				ivt.rotateRight(x.parent)
@@ -419,9 +429,9 @@ func (ivt *intervalTree) createIntervalNode(ivl Interval, val interface{}) *inte
 		iv:     IntervalValue{ivl, val},
 		max:    ivl.End,
 		c:      red,
-		left:   nil,
-		right:  nil,
-		parent: nil,
+		left:   ivt.sentinel,
+		right:  ivt.sentinel,
+		parent: ivt.sentinel,
 	}
 }
 
@@ -458,10 +468,10 @@ func (ivt *intervalTree) createIntervalNode(ivl Interval, val interface{}) *inte
 
 // Insert adds a node with the given interval into the tree.
 func (ivt *intervalTree) Insert(ivl Interval, val interface{}) {
-	var y *intervalNode
+	y := ivt.sentinel
 	z := ivt.createIntervalNode(ivl, val)
 	x := ivt.root
-	for x != nil {
+	for x != ivt.sentinel {
 		y = x
 		if z.iv.Ivl.Begin.Compare(x.iv.Ivl.Begin) < 0 {
 			x = x.left
@@ -471,7 +481,7 @@ func (ivt *intervalTree) Insert(ivl Interval, val interface{}) {
 	}
 
 	z.parent = y
-	if y == nil {
+	if y == ivt.sentinel {
 		ivt.root = z
 	} else {
 		if z.iv.Ivl.Begin.Compare(y.iv.Ivl.Begin) < 0 {
@@ -479,7 +489,7 @@ func (ivt *intervalTree) Insert(ivl Interval, val interface{}) {
 		} else {
 			y.right = z
 		}
-		y.updateMax()
+		y.updateMax(ivt.sentinel)
 	}
 	z.c = red
 
@@ -522,10 +532,11 @@ func (ivt *intervalTree) Insert(ivl Interval, val interface{}) {
 //	30. T.root.color = BLACK
 //
 func (ivt *intervalTree) insertFixup(z *intervalNode) {
-	for z.parent != nil && z.parent.parent != nil && z.parent.color() == red {
+	for z.parent.color(ivt.sentinel) == red {
 		if z.parent == z.parent.parent.left { // line 3-15
+
 			y := z.parent.parent.right
-			if y.color() == red {
+			if y.color(ivt.sentinel) == red {
 				y.c = black
 				z.parent.c = black
 				z.parent.parent.c = red
@@ -542,7 +553,7 @@ func (ivt *intervalTree) insertFixup(z *intervalNode) {
 		} else { // line 16-28
 			// same as then with left/right exchanged
 			y := z.parent.parent.left
-			if y.color() == red {
+			if y.color(ivt.sentinel) == red {
 				y.c = black
 				z.parent.c = black
 				z.parent.parent.c = red
@@ -588,23 +599,27 @@ func (ivt *intervalTree) insertFixup(z *intervalNode) {
 //	18. x.p = y
 //
 func (ivt *intervalTree) rotateLeft(x *intervalNode) {
+	// rotateLeft x must have right child
+	if x.right == ivt.sentinel {
+		return
+	}
+
 	// line 2-3
 	y := x.right
 	x.right = y.left
 
 	// line 5-6
-	if y.left != nil {
+	if y.left != ivt.sentinel {
 		y.left.parent = x
 	}
-
-	x.updateMax()
+	x.updateMax(ivt.sentinel)
 
 	// line 10-15, 18
 	ivt.replaceParent(x, y)
 
 	// line 17
 	y.left = x
-	y.updateMax()
+	y.updateMax(ivt.sentinel)
 }
 
 // rotateRight moves x so it is right of its left child
@@ -630,7 +645,8 @@ func (ivt *intervalTree) rotateLeft(x *intervalNode) {
 //	18. x.p = y
 //
 func (ivt *intervalTree) rotateRight(x *intervalNode) {
-	if x == nil {
+	// rotateRight x must have left child
+	if x.left == ivt.sentinel {
 		return
 	}
 
@@ -639,24 +655,23 @@ func (ivt *intervalTree) rotateRight(x *intervalNode) {
 	x.left = y.right
 
 	// line 5-6
-	if y.right != nil {
+	if y.right != ivt.sentinel {
 		y.right.parent = x
 	}
-
-	x.updateMax()
+	x.updateMax(ivt.sentinel)
 
 	// line 10-15, 18
 	ivt.replaceParent(x, y)
 
 	// line 17
 	y.right = x
-	y.updateMax()
+	y.updateMax(ivt.sentinel)
 }
 
 // replaceParent replaces x's parent with y
 func (ivt *intervalTree) replaceParent(x *intervalNode, y *intervalNode) {
 	y.parent = x.parent
-	if x.parent == nil {
+	if x.parent == ivt.sentinel {
 		ivt.root = y
 	} else {
 		if x == x.parent.left {
@@ -664,7 +679,7 @@ func (ivt *intervalTree) replaceParent(x *intervalNode, y *intervalNode) {
 		} else {
 			x.parent.right = y
 		}
-		x.parent.updateMax()
+		x.parent.updateMax(ivt.sentinel)
 	}
 	x.parent = y
 }
@@ -673,7 +688,7 @@ func (ivt *intervalTree) replaceParent(x *intervalNode, y *intervalNode) {
 func (ivt *intervalTree) Len() int { return ivt.count }
 
 // Height is the number of levels in the tree; one node has height 1.
-func (ivt *intervalTree) Height() int { return ivt.root.height() }
+func (ivt *intervalTree) Height() int { return ivt.root.height(ivt.sentinel) }
 
 // MaxHeight is the expected maximum tree height given the number of nodes
 func (ivt *intervalTree) MaxHeight() int {
@@ -686,11 +701,12 @@ type IntervalVisitor func(n *IntervalValue) bool
 // Visit calls a visitor function on every tree node intersecting the given interval.
 // It will visit each interval [x, y) in ascending order sorted on x.
 func (ivt *intervalTree) Visit(ivl Interval, ivv IntervalVisitor) {
-	ivt.root.visit(&ivl, func(n *intervalNode) bool { return ivv(&n.iv) })
+	ivt.root.visit(&ivl, ivt.sentinel, func(n *intervalNode) bool { return ivv(&n.iv) })
 }
 
 // find the exact node for a given interval
-func (ivt *intervalTree) find(ivl Interval) (ret *intervalNode) {
+func (ivt *intervalTree) find(ivl Interval) *intervalNode {
+	ret := ivt.sentinel
 	f := func(n *intervalNode) bool {
 		if n.iv.Ivl != ivl {
 			return true
@@ -698,14 +714,14 @@ func (ivt *intervalTree) find(ivl Interval) (ret *intervalNode) {
 		ret = n
 		return false
 	}
-	ivt.root.visit(&ivl, f)
+	ivt.root.visit(&ivl, ivt.sentinel, f)
 	return ret
 }
 
 // Find gets the IntervalValue for the node matching the given interval
 func (ivt *intervalTree) Find(ivl Interval) (ret *IntervalValue) {
 	n := ivt.find(ivl)
-	if n == nil {
+	if n == ivt.sentinel {
 		return nil
 	}
 	return &n.iv
@@ -714,14 +730,14 @@ func (ivt *intervalTree) Find(ivl Interval) (ret *IntervalValue) {
 // Intersects returns true if there is some tree node intersecting the given interval.
 func (ivt *intervalTree) Intersects(iv Interval) bool {
 	x := ivt.root
-	for x != nil && iv.Compare(&x.iv.Ivl) != 0 {
-		if x.left != nil && x.left.max.Compare(iv.Begin) > 0 {
+	for x != ivt.sentinel && iv.Compare(&x.iv.Ivl) != 0 {
+		if x.left != ivt.sentinel && x.left.max.Compare(iv.Begin) > 0 {
 			x = x.left
 		} else {
 			x = x.right
 		}
 	}
-	return x != nil
+	return x != ivt.sentinel
 }
 
 // Contains returns true if the interval tree's keys cover the entire given interval.
@@ -789,7 +805,7 @@ func (vi visitedInterval) String() string {
 // visitLevel traverses tree in level order.
 // used for testing
 func (ivt *intervalTree) visitLevel() []visitedInterval {
-	if ivt.root == nil {
+	if ivt.root == ivt.sentinel {
 		return nil
 	}
 
@@ -804,22 +820,21 @@ func (ivt *intervalTree) visitLevel() []visitedInterval {
 		f := queue[0]
 		queue = queue[1:]
 
-		ivt := visitedInterval{
+		vi := visitedInterval{
 			root:  f.node.iv.Ivl,
-			color: f.node.color(),
+			color: f.node.color(ivt.sentinel),
 			depth: f.depth,
 		}
-
-		if f.node.left != nil {
-			ivt.left = f.node.left.iv.Ivl
+		if f.node.left != ivt.sentinel {
+			vi.left = f.node.left.iv.Ivl
 			queue = append(queue, pair{f.node.left, f.depth + 1})
 		}
-		if f.node.right != nil {
-			ivt.right = f.node.right.iv.Ivl
+		if f.node.right != ivt.sentinel {
+			vi.right = f.node.right.iv.Ivl
 			queue = append(queue, pair{f.node.right, f.depth + 1})
 		}
 
-		rs = append(rs, ivt)
+		rs = append(rs, vi)
 	}
 
 	return rs

pkg/adt/interval_tree_test.go

@@ -280,25 +280,7 @@ func TestIntervalTreeDelete(t *testing.T) {
 	}
 	visitsAfterDelete11 := tr.visitLevel()
 	if !reflect.DeepEqual(expectedAfterDelete11, visitsAfterDelete11) {
-		// "black-height" property is violated here
-		//
-		// TODO: fix this
-		//                        [510,511]
-		//                         /      \
-		//               ----------        --------------------------
-		//              /                                            \
-		//          [82,83]                                       [830,831]
-		//                \                                      /          \
-		//                 \                                    /            \
-		//              [383,384]                        [647,648]           [899,900]
-		//              /       \                              \                 /    \
-		//             /         \                              \               /      \
-		//       [261,262]      [410,411]                      [815,816] [888,889]    [972,973]
-		//         /   \                                                                /
-		//        /     \                                                              /
-		// [238,239]   [292,293]                                                [953,954]
-		//
-		t.Logf("level order after deleting '11' expected %v, got %v", expectedAfterDelete11, visitsAfterDelete11)
+		t.Fatalf("level order after deleting '11' expected %v, got %v", expectedAfterDelete11, visitsAfterDelete11)
 	}
 }
 

pkg/logutil/zap.go

@@ -53,15 +53,12 @@ var DefaultZapLoggerConfig = zap.Config{
 	ErrorOutputPaths: []string{"stderr"},
 }
 
-// AddOutputPaths adds output paths to the existing output paths, resolving conflicts.
-func AddOutputPaths(cfg zap.Config, outputPaths, errorOutputPaths []string) zap.Config {
+// MergeOutputPaths merges logging output paths, resolving conflicts.
+func MergeOutputPaths(cfg zap.Config) zap.Config {
 	outputs := make(map[string]struct{})
 	for _, v := range cfg.OutputPaths {
 		outputs[v] = struct{}{}
 	}
-	for _, v := range outputPaths {
-		outputs[v] = struct{}{}
-	}
 	outputSlice := make([]string, 0)
 	if _, ok := outputs["/dev/null"]; ok {
 		// "/dev/null" to discard all
@@ -78,9 +75,6 @@ func AddOutputPaths(cfg zap.Config, outputPaths, errorOutputPaths []string) zap.
 	for _, v := range cfg.ErrorOutputPaths {
 		errOutputs[v] = struct{}{}
 	}
-	for _, v := range errorOutputPaths {
-		errOutputs[v] = struct{}{}
-	}
 	errOutputSlice := make([]string, 0)
 	if _, ok := errOutputs["/dev/null"]; ok {
 		// "/dev/null" to discard all

pkg/types/set.go

@@ -148,6 +148,14 @@ func (ts *tsafeSet) Contains(value string) (exists bool) {
 func (ts *tsafeSet) Equals(other Set) bool {
 	ts.m.RLock()
 	defer ts.m.RUnlock()
+
+	// If ts and other represent the same variable, avoid calling
+	// ts.us.Equals(other), to avoid double RLock bug
+	if _other, ok := other.(*tsafeSet); ok {
+		if _other == ts {
+			return true
+		}
+	}
 	return ts.us.Equals(other)
 }
 
@@ -173,6 +181,15 @@ func (ts *tsafeSet) Copy() Set {
 func (ts *tsafeSet) Sub(other Set) Set {
 	ts.m.RLock()
 	defer ts.m.RUnlock()
+
+	// If ts and other represent the same variable, avoid calling
+	// ts.us.Sub(other), to avoid double RLock bug
+	if _other, ok := other.(*tsafeSet); ok {
+		if _other == ts {
+			usResult := NewUnsafeSet()
+			return &tsafeSet{usResult, sync.RWMutex{}}
+		}
+	}
 	usResult := ts.us.Sub(other).(*unsafeSet)
 	return &tsafeSet{usResult, sync.RWMutex{}}
 }

proxy/grpcproxy/adapter/chan_stream.go

@@ -18,7 +18,9 @@ import (
 	"context"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 // chanServerStream implements grpc.ServerStream with a chanStream
@@ -120,7 +122,7 @@ func (s *chanStream) RecvMsg(m interface{}) error {
 		select {
 		case msg, ok := <-s.recvc:
 			if !ok {
-				return grpc.ErrClientConnClosing
+				return status.Error(codes.Canceled, "the client connection is closing")
 			}
 			if err, ok := msg.(error); ok {
 				return err

proxy/grpcproxy/lease.go

@@ -26,7 +26,9 @@ import (
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 type leaseProxy struct {
@@ -214,7 +216,7 @@ func (lp *leaseProxy) LeaseKeepAlive(stream pb.Lease_LeaseKeepAliveServer) error
 	case <-lostLeaderC:
 		return rpctypes.ErrNoLeader
 	case <-lp.leader.disconnectNotify():
-		return grpc.ErrClientConnClosing
+		return status.Error(codes.Canceled, "the client connection is closing")
 	default:
 		if err != nil {
 			return err

proxy/grpcproxy/watch.go

@@ -23,8 +23,9 @@ import (
 	"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
 	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
 
-	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
 )
 
 type watchProxy struct {
@@ -80,7 +81,7 @@ func (wp *watchProxy) Watch(stream pb.Watch_WatchServer) (err error) {
 		wp.mu.Unlock()
 		select {
 		case <-wp.leader.disconnectNotify():
-			return grpc.ErrClientConnClosing
+			return status.Error(codes.Canceled, "the client connection is closing")
 		default:
 			return wp.ctx.Err()
 		}
@@ -153,7 +154,7 @@ func (wp *watchProxy) Watch(stream pb.Watch_WatchServer) (err error) {
 	case <-lostLeaderC:
 		return rpctypes.ErrNoLeader
 	case <-wp.leader.disconnectNotify():
-		return grpc.ErrClientConnClosing
+		return status.Error(codes.Canceled, "the client connection is closing")
 	default:
 		return wps.ctx.Err()
 	}

raft/confchange/confchange.go

@@ -62,10 +62,7 @@ func (c Changer) EnterJoint(autoLeave bool, ccs ...pb.ConfChangeSingle) (tracker
 		return c.err(err)
 	}
 	// Clear the outgoing config.
-	{
-		*outgoingPtr(&cfg.Voters) = quorum.MajorityConfig{}
-
-	}
+	*outgoingPtr(&cfg.Voters) = quorum.MajorityConfig{}
 	// Copy incoming to outgoing.
 	for id := range incoming(cfg.Voters) {
 		outgoing(cfg.Voters)[id] = struct{}{}
@@ -260,11 +257,15 @@ func (c Changer) initProgress(cfg *tracker.Config, prs tracker.ProgressMap, id u
 		nilAwareAdd(&cfg.Learners, id)
 	}
 	prs[id] = &tracker.Progress{
-		// We initialize Progress.Next with lastIndex+1 so that the peer will be
-		// probed without an index first.
+		// Initializing the Progress with the last index means that the follower
+		// can be probed (with the last index).
 		//
-		// TODO(tbg): verify that, this is just my best guess.
-		Next:      c.LastIndex + 1,
+		// TODO(tbg): seems awfully optimistic. Using the first index would be
+		// better. The general expectation here is that the follower has no log
+		// at all (and will thus likely need a snapshot), though the app may
+		// have applied a snapshot out of band before adding the replica (thus
+		// making the first index the better choice).
+		Next:      c.LastIndex,
 		Match:     0,
 		Inflights: tracker.NewInflights(c.Tracker.MaxInflight),
 		IsLearner: isLearner,

raft/confchange/restore.go

@@ -0,0 +1,155 @@
+// Copyright 2019 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package confchange
+
+import (
+	pb "go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/raft/tracker"
+)
+
+// toConfChangeSingle translates a conf state into 1) a slice of operations creating
+// first the config that will become the outgoing one, and then the incoming one, and
+// b) another slice that, when applied to the config resulted from 1), represents the
+// ConfState.
+func toConfChangeSingle(cs pb.ConfState) (out []pb.ConfChangeSingle, in []pb.ConfChangeSingle) {
+	// Example to follow along this code:
+	// voters=(1 2 3) learners=(5) outgoing=(1 2 4 6) learners_next=(4)
+	//
+	// This means that before entering the joint config, the configuration
+	// had voters (1 2 4) and perhaps some learners that are already gone.
+	// The new set of voters is (1 2 3), i.e. (1 2) were kept around, and (4 6)
+	// are no longer voters; however 4 is poised to become a learner upon leaving
+	// the joint state.
+	// We can't tell whether 5 was a learner before entering the joint config,
+	// but it doesn't matter (we'll pretend that it wasn't).
+	//
+	// The code below will construct
+	// outgoing = add 1; add 2; add 4; add 6
+	// incoming = remove 1; remove 2; remove 4; remove 6
+	//            add 1;    add 2;    add 3;
+	//            add-learner 5;
+	//            add-learner 4;
+	//
+	// So, when starting with an empty config, after applying 'outgoing' we have
+	//
+	//   quorum=(1 2 4 6)
+	//
+	// From which we enter a joint state via 'incoming'
+	//
+	//   quorum=(1 2 3)&&(1 2 4 6) learners=(5) learners_next=(4)
+	//
+	// as desired.
+
+	for _, id := range cs.VotersOutgoing {
+		// If there are outgoing voters, first add them one by one so that the
+		// (non-joint) config has them all.
+		out = append(out, pb.ConfChangeSingle{
+			Type:   pb.ConfChangeAddNode,
+			NodeID: id,
+		})
+
+	}
+
+	// We're done constructing the outgoing slice, now on to the incoming one
+	// (which will apply on top of the config created by the outgoing slice).
+
+	// First, we'll remove all of the outgoing voters.
+	for _, id := range cs.VotersOutgoing {
+		in = append(in, pb.ConfChangeSingle{
+			Type:   pb.ConfChangeRemoveNode,
+			NodeID: id,
+		})
+	}
+	// Then we'll add the incoming voters and learners.
+	for _, id := range cs.Voters {
+		in = append(in, pb.ConfChangeSingle{
+			Type:   pb.ConfChangeAddNode,
+			NodeID: id,
+		})
+	}
+	for _, id := range cs.Learners {
+		in = append(in, pb.ConfChangeSingle{
+			Type:   pb.ConfChangeAddLearnerNode,
+			NodeID: id,
+		})
+	}
+	// Same for LearnersNext; these are nodes we want to be learners but which
+	// are currently voters in the outgoing config.
+	for _, id := range cs.LearnersNext {
+		in = append(in, pb.ConfChangeSingle{
+			Type:   pb.ConfChangeAddLearnerNode,
+			NodeID: id,
+		})
+	}
+	return out, in
+}
+
+func chain(chg Changer, ops ...func(Changer) (tracker.Config, tracker.ProgressMap, error)) (tracker.Config, tracker.ProgressMap, error) {
+	for _, op := range ops {
+		cfg, prs, err := op(chg)
+		if err != nil {
+			return tracker.Config{}, nil, err
+		}
+		chg.Tracker.Config = cfg
+		chg.Tracker.Progress = prs
+	}
+	return chg.Tracker.Config, chg.Tracker.Progress, nil
+}
+
+// Restore takes a Changer (which must represent an empty configuration), and
+// runs a sequence of changes enacting the configuration described in the
+// ConfState.
+//
+// TODO(tbg) it's silly that this takes a Changer. Unravel this by making sure
+// the Changer only needs a ProgressMap (not a whole Tracker) at which point
+// this can just take LastIndex and MaxInflight directly instead and cook up
+// the results from that alone.
+func Restore(chg Changer, cs pb.ConfState) (tracker.Config, tracker.ProgressMap, error) {
+	outgoing, incoming := toConfChangeSingle(cs)
+
+	var ops []func(Changer) (tracker.Config, tracker.ProgressMap, error)
+
+	if len(outgoing) == 0 {
+		// No outgoing config, so just apply the incoming changes one by one.
+		for _, cc := range incoming {
+			cc := cc // loop-local copy
+			ops = append(ops, func(chg Changer) (tracker.Config, tracker.ProgressMap, error) {
+				return chg.Simple(cc)
+			})
+		}
+	} else {
+		// The ConfState describes a joint configuration.
+		//
+		// First, apply all of the changes of the outgoing config one by one, so
+		// that it temporarily becomes the incoming active config. For example,
+		// if the config is (1 2 3)&(2 3 4), this will establish (2 3 4)&().
+		for _, cc := range outgoing {
+			cc := cc // loop-local copy
+			ops = append(ops, func(chg Changer) (tracker.Config, tracker.ProgressMap, error) {
+				return chg.Simple(cc)
+			})
+		}
+		// Now enter the joint state, which rotates the above additions into the
+		// outgoing config, and adds the incoming config in. Continuing the
+		// example above, we'd get (1 2 3)&(2 3 4), i.e. the incoming operations
+		// would be removing 2,3,4 and then adding in 1,2,3 while transitioning
+		// into a joint state.
+		ops = append(ops, func(chg Changer) (tracker.Config, tracker.ProgressMap, error) {
+			return chg.EnterJoint(cs.AutoLeave, incoming...)
+		})
+	}
+
+	return chain(chg, ops...)
+}

raft/confchange/restore_test.go

@@ -0,0 +1,142 @@
+// Copyright 2019 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package confchange
+
+import (
+	"math/rand"
+	"reflect"
+	"sort"
+	"testing"
+	"testing/quick"
+
+	pb "go.etcd.io/etcd/raft/raftpb"
+	"go.etcd.io/etcd/raft/tracker"
+)
+
+type rndConfChange pb.ConfState
+
+// Generate creates a random (valid) ConfState for use with quickcheck.
+func (rndConfChange) Generate(rand *rand.Rand, _ int) reflect.Value {
+	conv := func(sl []int) []uint64 {
+		// We want IDs but the incoming slice is zero-indexed, so add one to
+		// each.
+		out := make([]uint64, len(sl))
+		for i := range sl {
+			out[i] = uint64(sl[i] + 1)
+		}
+		return out
+	}
+	var cs pb.ConfState
+	// NB: never generate the empty ConfState, that one should be unit tested.
+	nVoters := 1 + rand.Intn(5)
+
+	nLearners := rand.Intn(5)
+	// The number of voters that are in the outgoing config but not in the
+	// incoming one. (We'll additionally retain a random number of the
+	// incoming voters below).
+	nRemovedVoters := rand.Intn(3)
+
+	// Voters, learners, and removed voters must not overlap. A "removed voter"
+	// is one that we have in the outgoing config but not the incoming one.
+	ids := conv(rand.Perm(2 * (nVoters + nLearners + nRemovedVoters)))
+
+	cs.Voters = ids[:nVoters]
+	ids = ids[nVoters:]
+
+	if nLearners > 0 {
+		cs.Learners = ids[:nLearners]
+		ids = ids[nLearners:]
+	}
+
+	// Roll the dice on how many of the incoming voters we decide were also
+	// previously voters.
+	//
+	// NB: this code avoids creating non-nil empty slices (here and below).
+	nOutgoingRetainedVoters := rand.Intn(nVoters + 1)
+	if nOutgoingRetainedVoters > 0 || nRemovedVoters > 0 {
+		cs.VotersOutgoing = append([]uint64(nil), cs.Voters[:nOutgoingRetainedVoters]...)
+		cs.VotersOutgoing = append(cs.VotersOutgoing, ids[:nRemovedVoters]...)
+	}
+	// Only outgoing voters that are not also incoming voters can be in
+	// LearnersNext (they represent demotions).
+	if nRemovedVoters > 0 {
+		if nLearnersNext := rand.Intn(nRemovedVoters + 1); nLearnersNext > 0 {
+			cs.LearnersNext = ids[:nLearnersNext]
+		}
+	}
+
+	cs.AutoLeave = len(cs.VotersOutgoing) > 0 && rand.Intn(2) == 1
+	return reflect.ValueOf(rndConfChange(cs))
+}
+
+func TestRestore(t *testing.T) {
+	cfg := quick.Config{MaxCount: 1000}
+
+	f := func(cs pb.ConfState) bool {
+		chg := Changer{
+			Tracker:   tracker.MakeProgressTracker(20),
+			LastIndex: 10,
+		}
+		cfg, prs, err := Restore(chg, cs)
+		if err != nil {
+			t.Error(err)
+			return false
+		}
+		chg.Tracker.Config = cfg
+		chg.Tracker.Progress = prs
+
+		for _, sl := range [][]uint64{
+			cs.Voters,
+			cs.Learners,
+			cs.VotersOutgoing,
+			cs.LearnersNext,
+		} {
+			sort.Slice(sl, func(i, j int) bool { return sl[i] < sl[j] })
+		}
+
+		cs2 := chg.Tracker.ConfState()
+		// NB: cs.Equivalent does the same "sorting" dance internally, but let's
+		// test it a bit here instead of relying on it.
+		if reflect.DeepEqual(cs, cs2) && cs.Equivalent(cs2) == nil && cs2.Equivalent(cs) == nil {
+			return true // success
+		}
+		t.Errorf(`
+before: %+#v
+after:  %+#v`, cs, cs2)
+		return false
+	}
+
+	ids := func(sl ...uint64) []uint64 {
+		return sl
+	}
+
+	// Unit tests.
+	for _, cs := range []pb.ConfState{
+		{},
+		{Voters: ids(1, 2, 3)},
+		{Voters: ids(1, 2, 3), Learners: ids(4, 5, 6)},
+		{Voters: ids(1, 2, 3), Learners: ids(5), VotersOutgoing: ids(1, 2, 4, 6), LearnersNext: ids(4)},
+	} {
+		if !f(cs) {
+			t.FailNow() // f() already logged a nice t.Error()
+		}
+	}
+
+	if err := quick.Check(func(cs rndConfChange) bool {
+		return f(pb.ConfState(cs))
+	}, &cfg); err != nil {
+		t.Error(err)
+	}
+}

raft/confchange/testdata/joint_autoleave.txt

@@ -5,16 +5,16 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 # Autoleave is reflected in the config.
 enter-joint autoleave=true
 v2 v3
 ----
 voters=(1 2 3)&&(1) autoleave
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
-3: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
+3: StateProbe match=0 next=1
 
 # Can't enter-joint twice, even if autoleave changes.
 enter-joint autoleave=false
@@ -24,6 +24,6 @@ config is already joint
 leave-joint
 ----
 voters=(1 2 3)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
-3: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
+3: StateProbe match=0 next=1

raft/confchange/testdata/joint_idempotency.txt

@@ -5,19 +5,19 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 enter-joint
 r1 r2 r9 v2 v3 v4 v2 v3 v4 l2 l2 r4 r4 l1 l1
 ----
 voters=(3)&&(1) learners=(2) learners_next=(1)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2 learner
-3: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1 learner
+3: StateProbe match=0 next=1
 
 leave-joint
 ----
 voters=(3) learners=(1 2)
-1: StateProbe match=0 next=1 learner
-2: StateProbe match=0 next=2 learner
-3: StateProbe match=0 next=2
+1: StateProbe match=0 next=0 learner
+2: StateProbe match=0 next=1 learner
+3: StateProbe match=0 next=1

raft/confchange/testdata/joint_learners_next.txt

@@ -8,17 +8,17 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 enter-joint
 v2 l1
 ----
 voters=(2)&&(1) learners_next=(1)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
 
 leave-joint
 ----
 voters=(2) learners=(1)
-1: StateProbe match=0 next=1 learner
-2: StateProbe match=0 next=2
+1: StateProbe match=0 next=0 learner
+2: StateProbe match=0 next=1

raft/confchange/testdata/joint_safety.txt

@@ -15,7 +15,7 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=4
+1: StateProbe match=0 next=3
 
 leave-joint
 ----
@@ -25,7 +25,7 @@ can't leave a non-joint config
 enter-joint
 ----
 voters=(1)&&(1)
-1: StateProbe match=0 next=4
+1: StateProbe match=0 next=3
 
 enter-joint
 ----
@@ -34,7 +34,7 @@ config is already joint
 leave-joint
 ----
 voters=(1)
-1: StateProbe match=0 next=4
+1: StateProbe match=0 next=3
 
 leave-joint
 ----
@@ -45,10 +45,10 @@ enter-joint
 r1 v2 v3 l4
 ----
 voters=(2 3)&&(1) learners=(4)
-1: StateProbe match=0 next=4
-2: StateProbe match=0 next=10
-3: StateProbe match=0 next=10
-4: StateProbe match=0 next=10 learner
+1: StateProbe match=0 next=3
+2: StateProbe match=0 next=9
+3: StateProbe match=0 next=9
+4: StateProbe match=0 next=9 learner
 
 enter-joint
 ----
@@ -67,15 +67,15 @@ can't apply simple config change in joint config
 leave-joint
 ----
 voters=(2 3) learners=(4)
-2: StateProbe match=0 next=10
-3: StateProbe match=0 next=10
-4: StateProbe match=0 next=10 learner
+2: StateProbe match=0 next=9
+3: StateProbe match=0 next=9
+4: StateProbe match=0 next=9 learner
 
 simple
 l9
 ----
 voters=(2 3) learners=(4 9)
-2: StateProbe match=0 next=10
-3: StateProbe match=0 next=10
-4: StateProbe match=0 next=10 learner
-9: StateProbe match=0 next=15 learner
+2: StateProbe match=0 next=9
+3: StateProbe match=0 next=9
+4: StateProbe match=0 next=9 learner
+9: StateProbe match=0 next=14 learner

raft/confchange/testdata/simple_idempotency.txt

@@ -2,68 +2,68 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 simple
 v2
 ----
 voters=(1 2)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=3
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=2
 
 simple
 l1
 ----
 voters=(2) learners=(1)
-1: StateProbe match=0 next=1 learner
-2: StateProbe match=0 next=3
+1: StateProbe match=0 next=0 learner
+2: StateProbe match=0 next=2
 
 simple
 l1
 ----
 voters=(2) learners=(1)
-1: StateProbe match=0 next=1 learner
-2: StateProbe match=0 next=3
+1: StateProbe match=0 next=0 learner
+2: StateProbe match=0 next=2
 
 simple
 r1
 ----
 voters=(2)
-2: StateProbe match=0 next=3
+2: StateProbe match=0 next=2
 
 simple
 r1
 ----
 voters=(2)
-2: StateProbe match=0 next=3
+2: StateProbe match=0 next=2
 
 simple
 v3
 ----
 voters=(2 3)
-2: StateProbe match=0 next=3
-3: StateProbe match=0 next=8
+2: StateProbe match=0 next=2
+3: StateProbe match=0 next=7
 
 simple
 r3
 ----
 voters=(2)
-2: StateProbe match=0 next=3
+2: StateProbe match=0 next=2
 
 simple
 r3
 ----
 voters=(2)
-2: StateProbe match=0 next=3
+2: StateProbe match=0 next=2
 
 simple
 r4
 ----
 voters=(2)
-2: StateProbe match=0 next=3
+2: StateProbe match=0 next=2

raft/confchange/testdata/simple_promote_demote.txt

@@ -4,22 +4,22 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 simple
 v2
 ----
 voters=(1 2)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
 
 simple
 v3
 ----
 voters=(1 2 3)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
-3: StateProbe match=0 next=3
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
+3: StateProbe match=0 next=2
 
 # Can atomically demote and promote without a hitch.
 # This is pointless, but possible.
@@ -27,18 +27,18 @@ simple
 l1 v1
 ----
 voters=(1 2 3)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
-3: StateProbe match=0 next=3
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
+3: StateProbe match=0 next=2
 
 # Can demote a voter.
 simple
 l2
 ----
 voters=(1 3) learners=(2)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2 learner
-3: StateProbe match=0 next=3
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1 learner
+3: StateProbe match=0 next=2
 
 # Can atomically promote and demote the same voter.
 # This is pointless, but possible.
@@ -46,15 +46,15 @@ simple
 v2 l2
 ----
 voters=(1 3) learners=(2)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2 learner
-3: StateProbe match=0 next=3
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1 learner
+3: StateProbe match=0 next=2
 
 # Can promote a voter.
 simple
 v2
 ----
 voters=(1 2 3)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
-3: StateProbe match=0 next=3
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
+3: StateProbe match=0 next=2

raft/confchange/testdata/simple_safety.txt

@@ -7,15 +7,15 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=2
+1: StateProbe match=0 next=1
 
 simple
 v2 l3
 ----
 voters=(1 2) learners=(3)
-1: StateProbe match=0 next=2
-2: StateProbe match=0 next=3
-3: StateProbe match=0 next=3 learner
+1: StateProbe match=0 next=1
+2: StateProbe match=0 next=2
+3: StateProbe match=0 next=2 learner
 
 simple
 r1 v5
@@ -46,11 +46,11 @@ simple
 l2 l3 l4 l5
 ----
 voters=(1) learners=(2 3 4 5)
-1: StateProbe match=0 next=2
-2: StateProbe match=0 next=3 learner
-3: StateProbe match=0 next=3 learner
-4: StateProbe match=0 next=9 learner
-5: StateProbe match=0 next=9 learner
+1: StateProbe match=0 next=1
+2: StateProbe match=0 next=2 learner
+3: StateProbe match=0 next=2 learner
+4: StateProbe match=0 next=8 learner
+5: StateProbe match=0 next=8 learner
 
 simple
 r1
@@ -61,4 +61,4 @@ simple
 r2 r3 r4 r5
 ----
 voters=(1)
-1: StateProbe match=0 next=2
+1: StateProbe match=0 next=1

raft/confchange/testdata/update.txt

@@ -6,18 +6,18 @@ simple
 v1
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0
 
 simple
 v2 u1
 ----
 voters=(1 2)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1
 
 simple
 u1 u2 u3 u1 u2 u3
 ----
 voters=(1 2)
-1: StateProbe match=0 next=1
-2: StateProbe match=0 next=2
+1: StateProbe match=0 next=0
+2: StateProbe match=0 next=1

raft/confchange/testdata/zero.txt

@@ -3,4 +3,4 @@ simple
 v1 r0 v0 l0
 ----
 voters=(1)
-1: StateProbe match=0 next=1
+1: StateProbe match=0 next=0

raft/interaction_test.go

@@ -0,0 +1,34 @@
+// Copyright 2019 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package raft_test
+
+import (
+	"testing"
+
+	"github.com/cockroachdb/datadriven"
+	"go.etcd.io/etcd/raft/rafttest"
+)
+
+func TestInteraction(t *testing.T) {
+	// NB: if this test fails, run `go test ./raft -rewrite` and inspect the
+	// diff. Only commit the changes if you understand what caused them and if
+	// they are desired.
+	datadriven.Walk(t, "testdata", func(t *testing.T, path string) {
+		env := rafttest.NewInteractionEnv(nil)
+		datadriven.RunTest(t, path, func(d *datadriven.TestData) string {
+			return env.Handle(t, *d)
+		})
+	})
+}

raft/log_test.go

@@ -265,7 +265,7 @@ func TestLogMaybeAppend(t *testing.T) {
 					t.Fatalf("unexpected error %v", err)
 				}
 				if !reflect.DeepEqual(tt.ents, gents) {
-					t.Errorf("%d: appended entries = %v, want %v", i, gents, tt.ents)
+					t.Errorf("#%d: appended entries = %v, want %v", i, gents, tt.ents)
 				}
 			}
 		}()
@@ -426,7 +426,7 @@ func TestUnstableEnts(t *testing.T) {
 
 		ents := raftLog.unstableEntries()
 		if l := len(ents); l > 0 {
-			raftLog.stableTo(ents[l-1].Index, ents[l-i].Term)
+			raftLog.stableTo(ents[l-1].Index, ents[l-1].Term)
 		}
 		if !reflect.DeepEqual(ents, tt.wents) {
 			t.Errorf("#%d: unstableEnts = %+v, want %+v", i, ents, tt.wents)
@@ -671,13 +671,13 @@ func TestIsOutOfBounds(t *testing.T) {
 			}()
 			err := l.mustCheckOutOfBounds(tt.lo, tt.hi)
 			if tt.wpanic {
-				t.Errorf("%d: panic = %v, want %v", i, false, true)
+				t.Errorf("#%d: panic = %v, want %v", i, false, true)
 			}
 			if tt.wErrCompacted && err != ErrCompacted {
-				t.Errorf("%d: err = %v, want %v", i, err, ErrCompacted)
+				t.Errorf("#%d: err = %v, want %v", i, err, ErrCompacted)
 			}
 			if !tt.wErrCompacted && err != nil {
-				t.Errorf("%d: unexpected err %v", i, err)
+				t.Errorf("#%d: unexpected err %v", i, err)
 			}
 		}()
 	}

raft/log_unstable.go

@@ -55,10 +55,7 @@ func (u *unstable) maybeLastIndex() (uint64, bool) {
 // is any.
 func (u *unstable) maybeTerm(i uint64) (uint64, bool) {
 	if i < u.offset {
-		if u.snapshot == nil {
-			return 0, false
-		}
-		if u.snapshot.Metadata.Index == i {
+		if u.snapshot != nil && u.snapshot.Metadata.Index == i {
 			return u.snapshot.Metadata.Term, true
 		}
 		return 0, false
@@ -71,6 +68,7 @@ func (u *unstable) maybeTerm(i uint64) (uint64, bool) {
 	if i > last {
 		return 0, false
 	}
+
 	return u.entries[i-u.offset].Term, true
 }
 

raft/quorum/majority.go

@@ -112,9 +112,7 @@ func (c MajorityConfig) Slice() []uint64 {
 	return sl
 }
 
-type uint64Slice []uint64
-
-func insertionSort(sl uint64Slice) {
+func insertionSort(sl []uint64) {
 	a, b := 0, len(sl)
 	for i := a + 1; i < b; i++ {
 		for j := i; j > a && sl[j] < sl[j-1]; j-- {
@@ -141,12 +139,12 @@ func (c MajorityConfig) CommittedIndex(l AckedIndexer) Index {
 	// performance is a lesser concern (additionally the performance
 	// implications of an allocation here are far from drastic).
 	var stk [7]uint64
-	srt := uint64Slice(stk[:])
-
-	if cap(srt) < n {
+	var srt []uint64
+	if len(stk) >= n {
+		srt = stk[:n]
+	} else {
 		srt = make([]uint64, n)
 	}
-	srt = srt[:n]
 
 	{
 		// Fill the slice with the indexes observed. Any unused slots will be

raft/raft.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"math"
 	"math/rand"
+	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -263,7 +264,8 @@ type raft struct {
 
 	maxMsgSize         uint64
 	maxUncommittedSize uint64
-	prs                tracker.ProgressTracker
+	// TODO(tbg): rename to trk.
+	prs tracker.ProgressTracker
 
 	state StateType
 
@@ -327,18 +329,18 @@ func newRaft(c *Config) *raft {
 	if err != nil {
 		panic(err) // TODO(bdarnell)
 	}
-	peers := c.peers
-	learners := c.learners
-	if len(cs.Voters) > 0 || len(cs.Learners) > 0 {
-		if len(peers) > 0 || len(learners) > 0 {
+
+	if len(c.peers) > 0 || len(c.learners) > 0 {
+		if len(cs.Voters) > 0 || len(cs.Learners) > 0 {
 			// TODO(bdarnell): the peers argument is always nil except in
 			// tests; the argument should be removed and these tests should be
 			// updated to specify their nodes through a snapshot.
 			panic("cannot specify both newRaft(peers, learners) and ConfState.(Voters, Learners)")
 		}
-		peers = cs.Voters
-		learners = cs.Learners
+		cs.Voters = c.peers
+		cs.Learners = c.learners
 	}
+
 	r := &raft{
 		id:                        c.ID,
 		lead:                      None,
@@ -355,16 +357,17 @@ func newRaft(c *Config) *raft {
 		readOnly:                  newReadOnly(c.ReadOnlyOption),
 		disableProposalForwarding: c.DisableProposalForwarding,
 	}
-	for _, p := range peers {
-		// Add node to active config.
-		r.applyConfChange(pb.ConfChange{Type: pb.ConfChangeAddNode, NodeID: p}.AsV2())
-	}
-	for _, p := range learners {
-		// Add learner to active config.
-		r.applyConfChange(pb.ConfChange{Type: pb.ConfChangeAddLearnerNode, NodeID: p}.AsV2())
-	}
 
-	if !isHardStateEqual(hs, emptyState) {
+	cfg, prs, err := confchange.Restore(confchange.Changer{
+		Tracker:   r.prs,
+		LastIndex: raftlog.lastIndex(),
+	}, cs)
+	if err != nil {
+		panic(err)
+	}
+	assertConfStatesEquivalent(r.logger, cs, r.switchToConfig(cfg, prs))
+
+	if !IsEmptyHardState(hs) {
 		r.loadState(hs)
 	}
 	if c.Applied > 0 {
@@ -527,7 +530,6 @@ func (r *raft) bcastAppend() {
 		if id == r.id {
 			return
 		}
-
 		r.sendAppend(id)
 	})
 }
@@ -793,7 +795,16 @@ func (r *raft) campaign(t CampaignType) {
 		}
 		return
 	}
-	for id := range r.prs.Voters.IDs() {
+	var ids []uint64
+	{
+		idMap := r.prs.Voters.IDs()
+		ids = make([]uint64, 0, len(idMap))
+		for id := range idMap {
+			ids = append(ids, id)
+		}
+		sort.Slice(ids, func(i, j int) bool { return ids[i] < ids[j] })
+	}
+	for _, id := range ids {
 		if id == r.id {
 			continue
 		}
@@ -920,12 +931,6 @@ func (r *raft) Step(m pb.Message) error {
 		}
 
 	case pb.MsgVote, pb.MsgPreVote:
-		if r.isLearner {
-			// TODO: learner may need to vote, in case of node down when confchange.
-			r.logger.Infof("%x [logterm: %d, index: %d, vote: %x] ignored %s from %x [logterm: %d, index: %d] at term %d: learner can not vote",
-				r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.Type, m.From, m.LogTerm, m.Index, r.Term)
-			return nil
-		}
 		// We can vote if this is a repeat of a vote we've already cast...
 		canVote := r.Vote == m.From ||
 			// ...we haven't voted and we don't think there's a leader yet in this term...
@@ -934,6 +939,24 @@ func (r *raft) Step(m pb.Message) error {
 			(m.Type == pb.MsgPreVote && m.Term > r.Term)
 		// ...and we believe the candidate is up to date.
 		if canVote && r.raftLog.isUpToDate(m.Index, m.LogTerm) {
+			// Note: it turns out that that learners must be allowed to cast votes.
+			// This seems counter- intuitive but is necessary in the situation in which
+			// a learner has been promoted (i.e. is now a voter) but has not learned
+			// about this yet.
+			// For example, consider a group in which id=1 is a learner and id=2 and
+			// id=3 are voters. A configuration change promoting 1 can be committed on
+			// the quorum `{2,3}` without the config change being appended to the
+			// learner's log. If the leader (say 2) fails, there are de facto two
+			// voters remaining. Only 3 can win an election (due to its log containing
+			// all committed entries), but to do so it will need 1 to vote. But 1
+			// considers itself a learner and will continue to do so until 3 has
+			// stepped up as leader, replicates the conf change to 1, and 1 applies it.
+			// Ultimately, by receiving a request to vote, the learner realizes that
+			// the candidate believes it to be a voter, and that it should act
+			// accordingly. The candidate's config may be stale, too; but in that case
+			// it won't win the election, at least in the absence of the bug discussed
+			// in:
+			// https://github.com/etcd-io/etcd/issues/7625#issuecomment-488798263.
 			r.logger.Infof("%x [logterm: %d, index: %d, vote: %x] cast %s for %x [logterm: %d, index: %d] at term %d",
 				r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.Type, m.From, m.LogTerm, m.Index, r.Term)
 			// When responding to Msg{Pre,}Vote messages we include the term
@@ -1013,10 +1036,36 @@ func stepLeader(r *raft, m pb.Message) error {
 
 		for i := range m.Entries {
 			e := &m.Entries[i]
-			if e.Type == pb.EntryConfChange || e.Type == pb.EntryConfChangeV2 {
-				if r.pendingConfIndex > r.raftLog.applied {
-					r.logger.Infof("%x propose conf %s ignored since pending unapplied configuration [index %d, applied %d]",
-						r.id, e, r.pendingConfIndex, r.raftLog.applied)
+			var cc pb.ConfChangeI
+			if e.Type == pb.EntryConfChange {
+				var ccc pb.ConfChange
+				if err := ccc.Unmarshal(e.Data); err != nil {
+					panic(err)
+				}
+				cc = ccc
+			} else if e.Type == pb.EntryConfChangeV2 {
+				var ccc pb.ConfChangeV2
+				if err := ccc.Unmarshal(e.Data); err != nil {
+					panic(err)
+				}
+				cc = ccc
+			}
+			if cc != nil {
+				alreadyPending := r.pendingConfIndex > r.raftLog.applied
+				alreadyJoint := len(r.prs.Config.Voters[1]) > 0
+				wantsLeaveJoint := len(cc.AsV2().Changes) == 0
+
+				var refused string
+				if alreadyPending {
+					refused = fmt.Sprintf("possible unapplied conf change at index %d (applied to %d)", r.pendingConfIndex, r.raftLog.applied)
+				} else if alreadyJoint && !wantsLeaveJoint {
+					refused = "must transition out of joint config first"
+				} else if !alreadyJoint && wantsLeaveJoint {
+					refused = "not in joint state; refusing empty conf change"
+				}
+
+				if refused != "" {
+					r.logger.Infof("%x ignoring conf change %v at config %s: %s", r.id, cc, r.prs.Config, refused)
 					m.Entries[i] = pb.Entry{Type: pb.EntryNormal}
 				} else {
 					r.pendingConfIndex = r.raftLog.lastIndex() + uint64(i) + 1
@@ -1050,7 +1099,7 @@ func stepLeader(r *raft, m pb.Message) error {
 			case ReadOnlyLeaseBased:
 				ri := r.raftLog.committed
 				if m.From == None || m.From == r.id { // from local member
-					r.readStates = append(r.readStates, ReadState{Index: r.raftLog.committed, RequestCtx: m.Entries[0].Data})
+					r.readStates = append(r.readStates, ReadState{Index: ri, RequestCtx: m.Entries[0].Data})
 				} else {
 					r.send(pb.Message{To: m.From, Type: pb.MsgReadIndexResp, Index: ri, Entries: m.Entries})
 				}
@@ -1418,13 +1467,19 @@ func (r *raft) restore(s pb.Snapshot) bool {
 
 	// Reset the configuration and add the (potentially updated) peers in anew.
 	r.prs = tracker.MakeProgressTracker(r.prs.MaxInflight)
-	for _, id := range s.Metadata.ConfState.Voters {
-		r.applyConfChange(pb.ConfChange{NodeID: id, Type: pb.ConfChangeAddNode}.AsV2())
-	}
-	for _, id := range s.Metadata.ConfState.Learners {
-		r.applyConfChange(pb.ConfChange{NodeID: id, Type: pb.ConfChangeAddLearnerNode}.AsV2())
+	cfg, prs, err := confchange.Restore(confchange.Changer{
+		Tracker:   r.prs,
+		LastIndex: r.raftLog.lastIndex(),
+	}, cs)
+
+	if err != nil {
+		// This should never happen. Either there's a bug in our config change
+		// handling or the client corrupted the conf change.
+		panic(fmt.Sprintf("unable to restore config %+v: %s", cs, err))
 	}
 
+	assertConfStatesEquivalent(r.logger, cs, r.switchToConfig(cfg, prs))
+
 	pr := r.prs.Progress[r.id]
 	pr.MaybeUpdate(pr.Next - 1) // TODO(tbg): this is untested and likely unneeded
 
@@ -1459,19 +1514,21 @@ func (r *raft) applyConfChange(cc pb.ConfChangeV2) pb.ConfState {
 		panic(err)
 	}
 
+	return r.switchToConfig(cfg, prs)
+}
+
+// switchToConfig reconfigures this node to use the provided configuration. It
+// updates the in-memory state and, when necessary, carries out additional
+// actions such as reacting to the removal of nodes or changed quorum
+// requirements.
+//
+// The inputs usually result from restoring a ConfState or applying a ConfChange.
+func (r *raft) switchToConfig(cfg tracker.Config, prs tracker.ProgressMap) pb.ConfState {
 	r.prs.Config = cfg
 	r.prs.Progress = prs
 
 	r.logger.Infof("%x switched to configuration %s", r.id, r.prs.Config)
-	// Now that the configuration is updated, handle any side effects.
-
-	cs := pb.ConfState{
-		Voters:         r.prs.Voters[0].Slice(),
-		VotersOutgoing: r.prs.Voters[1].Slice(),
-		Learners:       quorum.MajorityConfig(r.prs.Learners).Slice(),
-		LearnersNext:   quorum.MajorityConfig(r.prs.LearnersNext).Slice(),
-		AutoLeave:      r.prs.AutoLeave,
-	}
+	cs := r.prs.ConfState()
 	pr, ok := r.prs.Progress[r.id]
 
 	// Update whether the node itself is a learner, resetting to false when the
@@ -1496,10 +1553,18 @@ func (r *raft) applyConfChange(cc pb.ConfChangeV2) pb.ConfState {
 	if r.state != StateLeader || len(cs.Voters) == 0 {
 		return cs
 	}
+
 	if r.maybeCommit() {
-		// The quorum size may have been reduced (but not to zero), so see if
-		// any pending entries can be committed.
+		// If the configuration change means that more entries are committed now,
+		// broadcast/append to everyone in the updated config.
 		r.bcastAppend()
+	} else {
+		// Otherwise, still probe the newly added replicas; there's no reason to
+		// let them wait out a heartbeat interval (or the next incoming
+		// proposal).
+		r.prs.Visit(func(id uint64, pr *tracker.Progress) {
+			r.maybeSendAppend(id, false /* sendIfEmpty */)
+		})
 	}
 	// If the the leadTransferee was removed, abort the leadership transfer.
 	if _, tOK := r.prs.Progress[r.leadTransferee]; !tOK && r.leadTransferee != 0 {

raft/raft_snap_test.go

@@ -18,7 +18,6 @@ import (
 	"testing"
 
 	pb "go.etcd.io/etcd/raft/raftpb"
-	"go.etcd.io/etcd/raft/tracker"
 )
 
 var (
@@ -112,125 +111,6 @@ func TestSnapshotSucceed(t *testing.T) {
 	}
 }
 
-// TestSnapshotSucceedViaAppResp regression tests the situation in which a snap-
-// shot is sent to a follower at the most recent index (i.e. the snapshot index
-// is the leader's last index is the committed index). In that situation, a bug
-// in the past left the follower in probing status until the next log entry was
-// committed.
-func TestSnapshotSucceedViaAppResp(t *testing.T) {
-	s1 := NewMemoryStorage()
-	// Create a single-node leader.
-	n1 := newTestRaft(1, []uint64{1}, 10, 1, s1)
-	n1.becomeCandidate()
-	n1.becomeLeader()
-	// We need to add a second empty entry so that we can truncate the first
-	// one away.
-	n1.Step(pb.Message{Type: pb.MsgProp, Entries: []pb.Entry{{}}})
-
-	rd := newReady(n1, &SoftState{}, pb.HardState{})
-	s1.Append(rd.Entries)
-	s1.SetHardState(rd.HardState)
-
-	if exp, ci := s1.lastIndex(), n1.raftLog.committed; ci != exp {
-		t.Fatalf("unexpected committed index %d, wanted %d: %+v", ci, exp, s1)
-	}
-
-	// Force a log truncation.
-	if err := s1.Compact(1); err != nil {
-		t.Fatal(err)
-	}
-
-	// Add a follower to the group. Do this in a clandestine way for simplicity.
-	// Also set up a snapshot that will be sent to the follower.
-	n1.applyConfChange(pb.ConfChange{NodeID: 2, Type: pb.ConfChangeAddNode}.AsV2())
-	s1.snapshot = pb.Snapshot{
-		Metadata: pb.SnapshotMetadata{
-			ConfState: pb.ConfState{Voters: []uint64{1, 2}},
-			Index:     s1.lastIndex(),
-			Term:      s1.ents[len(s1.ents)-1].Term,
-		},
-	}
-
-	noMessage := pb.MessageType(-1)
-	mustSend := func(from, to *raft, typ pb.MessageType) pb.Message {
-		t.Helper()
-		for i, msg := range from.msgs {
-			if msg.From != from.id || msg.To != to.id || msg.Type != typ {
-				continue
-			}
-			t.Log(DescribeMessage(msg, func([]byte) string { return "" }))
-			if len(msg.Entries) > 0 {
-				t.Log(DescribeEntries(msg.Entries, func(b []byte) string { return string(b) }))
-			}
-			if err := to.Step(msg); err != nil {
-				t.Fatalf("%v: %s", msg, err)
-			}
-			from.msgs = append(from.msgs[:i], from.msgs[i+1:]...)
-			return msg
-		}
-		if typ == noMessage {
-			if len(from.msgs) == 0 {
-				return pb.Message{}
-			}
-			t.Fatalf("expected no more messages, but got %d->%d %v", from.id, to.id, from.msgs)
-		}
-		t.Fatalf("message %d->%d %s not found in %v", from.id, to.id, typ, from.msgs)
-		return pb.Message{} // unreachable
-	}
-
-	// Create the follower that will receive the snapshot.
-	s2 := NewMemoryStorage()
-	n2 := newTestRaft(2, []uint64{1, 2}, 10, 1, s2)
-
-	// Let the leader probe the follower.
-	if !n1.maybeSendAppend(2, true /* sendIfEmpty */) {
-		t.Fatalf("expected message to be sent")
-	}
-	if msg := mustSend(n1, n2, pb.MsgApp); len(msg.Entries) > 0 {
-		// For this test to work, the leader must not have anything to append
-		// to the follower right now.
-		t.Fatalf("unexpectedly appending entries %v", msg.Entries)
-	}
-
-	// Follower rejects the append (because it doesn't have any log entries)
-	if msg := mustSend(n2, n1, pb.MsgAppResp); !msg.Reject {
-		t.Fatalf("expected a rejection with zero hint, got reject=%t hint=%d", msg.Reject, msg.RejectHint)
-	}
-
-	const expIdx = 2
-	// Leader sends snapshot due to RejectHint of zero (we set up the raft log
-	// to start at index 2).
-	if msg := mustSend(n1, n2, pb.MsgSnap); msg.Snapshot.Metadata.Index != expIdx {
-		t.Fatalf("expected snapshot at index %d, got %d", expIdx, msg.Snapshot.Metadata.Index)
-	}
-
-	// n2 reacts to snapshot with MsgAppResp.
-	if msg := mustSend(n2, n1, pb.MsgAppResp); msg.Index != expIdx {
-		t.Fatalf("expected AppResp at index %d, got %d", expIdx, msg.Index)
-	}
-
-	// Leader sends MsgApp to communicate commit index.
-	if msg := mustSend(n1, n2, pb.MsgApp); msg.Commit != expIdx {
-		t.Fatalf("expected commit index %d, got %d", expIdx, msg.Commit)
-	}
-
-	// Follower responds.
-	mustSend(n2, n1, pb.MsgAppResp)
-
-	// Leader has correct state for follower.
-	pr := n1.prs.Progress[2]
-	if pr.State != tracker.StateReplicate {
-		t.Fatalf("unexpected state %v", pr)
-	}
-	if pr.Match != expIdx || pr.Next != expIdx+1 {
-		t.Fatalf("expected match = %d, next = %d; got match = %d and next = %d", expIdx, expIdx+1, pr.Match, pr.Next)
-	}
-
-	// Leader and follower are done.
-	mustSend(n1, n2, noMessage)
-	mustSend(n2, n1, noMessage)
-}
-
 func TestSnapshotAbort(t *testing.T) {
 	storage := NewMemoryStorage()
 	sm := newTestRaft(1, []uint64{1, 2}, 10, 1, storage)

raft/raft_test.go

@@ -378,16 +378,21 @@ func TestLearnerPromotion(t *testing.T) {
 	}
 }
 
-// TestLearnerCannotVote checks that a learner can't vote even it receives a valid Vote request.
-func TestLearnerCannotVote(t *testing.T) {
+// TestLearnerCanVote checks that a learner can vote when it receives a valid Vote request.
+// See (*raft).Step for why this is necessary and correct behavior.
+func TestLearnerCanVote(t *testing.T) {
 	n2 := newTestLearnerRaft(2, []uint64{1}, []uint64{2}, 10, 1, NewMemoryStorage())
 
 	n2.becomeFollower(1, None)
 
 	n2.Step(pb.Message{From: 1, To: 2, Term: 2, Type: pb.MsgVote, LogTerm: 11, Index: 11})
 
-	if len(n2.msgs) != 0 {
-		t.Errorf("expect learner not to vote, but received %v messages", n2.msgs)
+	if len(n2.msgs) != 1 {
+		t.Fatalf("expected exactly one message, not %+v", n2.msgs)
+	}
+	msg := n2.msgs[0]
+	if msg.Type != pb.MsgVoteResp && !msg.Reject {
+		t.Fatal("expected learner to not reject vote")
 	}
 }