The TestV3WatchRestoreSnapshotUnsync setups three members' cluster.
Before serving any update requests from client, after leader elected,
each member will have index 8 log: 3 x ConfChange +
3 x ClusterMemberAttrSet + 1 x ClusterVersionSet.
Based on the config (SnapshotCount: 10, CatchUpCount: 5), we need to
file update requests to trigger snapshot at least twice.
T1: L(snapshot-index: 11, compacted-index: 6) F_m0(index: 8)
T2: L(snapshot-index: 22, compacted-index: 17) F_m0(index: 8, out of date)
After member0 recovers from network partition, it will reject leader's
request and return hint (index:8, term:x). If it happens after
second snapshot, leader will find out the index:8 is out of date and
force to transfer snapshot.
However, the client only files 15 update requests and leader doesn't
finish the process of snapshot in time. Since the last of
compacted-index is 6, leader can still replicate index:9 to member0
instead of snapshot.
```bash
cd tests/integration
CLUSTER_DEBUG=true go test -v -count=1 -run TestV3WatchRestoreSnapshotUnsync ./
...
INFO m2.raft 3da8ba707f1a21a4 became leader at term 2 {"member": "m2"}
...
INFO m2 triggering snapshot {"member": "m2", "local-member-id": "3da8ba707f1a21a4", "local-member-applied-index": 22, "local-member-snapshot-index": 11, "local-member-snapshot-count": 10, "snapshot-forced": false}
...
cluster.go:1359: network partition between: 99626fe5001fde8b <-> 1c964119da6db036
cluster.go:1359: network partition between: 99626fe5001fde8b <-> 3da8ba707f1a21a4
cluster.go:416: WaitMembersForLeader
INFO m0.raft 99626fe5001fde8b became follower at term 2 {"member": "m0"}
INFO m0.raft raft.node: 99626fe5001fde8b elected leader 3da8ba707f1a21a4 at term 2 {"member": "m0"}
DEBUG m2.raft 3da8ba707f1a21a4 received MsgAppResp(rejected, hint: (index 8, term 2)) from 99626fe5001fde8b for index 23 {"member": "m2"}
DEBUG m2.raft 3da8ba707f1a21a4 decreased progress of 99626fe5001fde8b to [StateReplicate match=8 next=9 inflight=15] {"member": "m2"}
DEBUG m0 Applying entries {"member": "m0", "num-entries": 15}
DEBUG m0 Applying entry {"member": "m0", "index": 9, "term": 2, "type": "EntryNormal"}
....
INFO m2 saved snapshot {"member": "m2", "snapshot-index": 22}
INFO m2 compacted Raft logs {"member": "m2", "compact-index": 17}
```
To fix this issue, the patch uses log monitor to watch "compacted Raft
log" and expect that two members should compact log twice.
Fixes: #15545
Signed-off-by: Wei Fu <fuweid89@gmail.com>
This issue is somewhat easily reproduced simply by bombarding the
server with requests for progress notifications, which eventually
leads to one being delivered ahead of the payload message. This is
then caught by the watch response validation code previously added by
Marek Siarkowicz.
Signed-off-by: Peter Wortmann <peter.wortmann@skao.int>
This will fail basically every time, as the progress notification
request catches the watcher in an asynchronised state.
Signed-off-by: Peter Wortmann <peter.wortmann@skao.int>
Difference in load configuration for watch delay tests show how huge the
impact is. Even with random write scheduler grpc under http
server can only handle 500 KB with 2 seconds delay. On the other hand,
separate grpc server easily hits 10, 100 or even 1000 MB within 100 miliseconds.
Priority write scheduler that was used in most previous releases
is far worse than random one.
Tests configured to only 5 MB to avoid flakes and taking too long to fill
etcd.
Signed-off-by: Marek Siarkowicz <siarkowicz@google.com>
