version: bump to v3.0.10

Was racing with Watch() when closing the grpc stream on no watchers.

Fixes #6476

auth/range_perm_cache.go

@@ -22,7 +22,10 @@ import (
 	"github.com/coreos/etcd/mvcc/backend"
 )
 
-// isSubset returns true if a is a subset of b
+// isSubset returns true if a is a subset of b.
+// If a is a prefix of b, then a is a subset of b.
+// Given intervals [a1,a2) and [b1,b2), is
+// the a interval a subset of b?
 func isSubset(a, b *rangePerm) bool {
 	switch {
 	case len(a.end) == 0 && len(b.end) == 0:
@@ -32,9 +35,11 @@ func isSubset(a, b *rangePerm) bool {
 		// b is a key, a is a range
 		return false
 	case len(a.end) == 0:
-		return 0 <= bytes.Compare(a.begin, b.begin) && bytes.Compare(a.begin, b.end) <= 0
+		// a is a key, b is a range. need b1 <= a1 and a1 < b2
+		return bytes.Compare(b.begin, a.begin) <= 0 && bytes.Compare(a.begin, b.end) < 0
 	default:
-		return 0 <= bytes.Compare(a.begin, b.begin) && bytes.Compare(a.end, b.end) <= 0
+		// both are ranges. need b1 <= a1 and a2 <= b2
+		return bytes.Compare(b.begin, a.begin) <= 0 && bytes.Compare(a.end, b.end) <= 0
 	}
 }
 
@@ -88,12 +93,18 @@ func mergeRangePerms(perms []*rangePerm) []*rangePerm {
 	i := 0
 	for i < len(perms) {
 		begin, next := i, i
-		for next+1 < len(perms) && bytes.Compare(perms[next].end, perms[next+1].begin) != -1 {
+		for next+1 < len(perms) && bytes.Compare(perms[next].end, perms[next+1].begin) >= 0 {
 			next++
 		}
-
-		merged = append(merged, &rangePerm{begin: perms[begin].begin, end: perms[next].end})
-
+		// don't merge ["a", "b") with ["b", ""), because perms[next+1].end is empty.
+		if next != begin && len(perms[next].end) > 0 {
+			merged = append(merged, &rangePerm{begin: perms[begin].begin, end: perms[next].end})
+		} else {
+			merged = append(merged, perms[begin])
+			if next != begin {
+				merged = append(merged, perms[next])
+			}
+		}
 		i = next + 1
 	}
 

auth/range_perm_cache_test.go

@@ -46,6 +46,10 @@ func TestGetMergedPerms(t *testing.T) {
 			[]*rangePerm{{[]byte("a"), []byte("b")}},
 			[]*rangePerm{{[]byte("a"), []byte("b")}},
 		},
+		{
+			[]*rangePerm{{[]byte("a"), []byte("b")}, {[]byte("b"), []byte("")}},
+			[]*rangePerm{{[]byte("a"), []byte("b")}, {[]byte("b"), []byte("")}},
+		},
 		{
 			[]*rangePerm{{[]byte("a"), []byte("b")}, {[]byte("b"), []byte("c")}},
 			[]*rangePerm{{[]byte("a"), []byte("c")}},
@@ -106,7 +110,7 @@ func TestGetMergedPerms(t *testing.T) {
 		},
 		{
 			[]*rangePerm{{[]byte("a"), []byte("")}, {[]byte("b"), []byte("c")}, {[]byte("b"), []byte("")}, {[]byte("c"), []byte("")}, {[]byte("d"), []byte("")}},
-			[]*rangePerm{{[]byte("a"), []byte("")}, {[]byte("b"), []byte("c")}, {[]byte("d"), []byte("")}},
+			[]*rangePerm{{[]byte("a"), []byte("")}, {[]byte("b"), []byte("c")}, {[]byte("c"), []byte("")}, {[]byte("d"), []byte("")}},
 		},
 		// duplicate ranges
 		{

clientv3/balancer.go

@@ -45,6 +45,8 @@ type simpleBalancer struct {
 	// pinAddr is the currently pinned address; set to the empty string on
 	// intialization and shutdown.
 	pinAddr string
+
+	closed bool
 }
 
 func newSimpleBalancer(eps []string) *simpleBalancer {
@@ -74,15 +76,25 @@ func (b *simpleBalancer) ConnectNotify() <-chan struct{} {
 
 func (b *simpleBalancer) Up(addr grpc.Address) func(error) {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	// gRPC might call Up after it called Close. We add this check
+	// to "fix" it up at application layer. Or our simplerBalancer
+	// might panic since b.upc is closed.
+	if b.closed {
+		return func(err error) {}
+	}
+
 	if len(b.upEps) == 0 {
 		// notify waiting Get()s and pin first connected address
 		close(b.upc)
 		b.pinAddr = addr.Addr
 	}
 	b.upEps[addr.Addr] = struct{}{}
-	b.mu.Unlock()
+
 	// notify client that a connection is up
 	b.readyOnce.Do(func() { close(b.readyc) })
+
 	return func(err error) {
 		b.mu.Lock()
 		delete(b.upEps, addr.Addr)
@@ -128,13 +140,19 @@ func (b *simpleBalancer) Notify() <-chan []grpc.Address { return b.notifyCh }
 
 func (b *simpleBalancer) Close() error {
 	b.mu.Lock()
+	defer b.mu.Unlock()
+	// In case gRPC calls close twice. TODO: remove the checking
+	// when we are sure that gRPC wont call close twice.
+	if b.closed {
+		return nil
+	}
+	b.closed = true
 	close(b.notifyCh)
 	// terminate all waiting Get()s
 	b.pinAddr = ""
 	if len(b.upEps) == 0 {
 		close(b.upc)
 	}
-	b.mu.Unlock()
 	return nil
 }
 

clientv3/watch.go

@@ -127,6 +127,8 @@ type watchGrpcStream struct {
 	donec chan struct{}
 	// errc transmits errors from grpc Recv to the watch stream reconn logic
 	errc chan error
+	// closingc gets the watcherStream of closing watchers
+	closingc chan *watcherStream
 
 	// the error that closed the watch stream
 	closeErr error
@@ -189,11 +191,12 @@ func (w *watcher) newWatcherGrpcStream(inctx context.Context) *watchGrpcStream {
 		cancel:  cancel,
 		streams: make(map[int64]*watcherStream),
 
-		respc: make(chan *pb.WatchResponse),
-		reqc:  make(chan *watchRequest),
-		stopc: make(chan struct{}),
-		donec: make(chan struct{}),
-		errc:  make(chan error, 1),
+		respc:    make(chan *pb.WatchResponse),
+		reqc:     make(chan *watchRequest),
+		stopc:    make(chan struct{}),
+		donec:    make(chan struct{}),
+		errc:     make(chan error, 1),
+		closingc: make(chan *watcherStream),
 	}
 	go wgs.run()
 	return wgs
@@ -242,7 +245,6 @@ func (w *watcher) Watch(ctx context.Context, key string, opts ...OpOption) Watch
 	case reqc <- wr:
 		ok = true
 	case <-wr.ctx.Done():
-		wgs.stopIfEmpty()
 	case <-donec:
 		if wgs.closeErr != nil {
 			closeCh <- WatchResponse{closeErr: wgs.closeErr}
@@ -352,15 +354,19 @@ func (w *watchGrpcStream) addStream(resp *pb.WatchResponse, pendingReq *watchReq
 	go w.serveStream(ws)
 }
 
-// closeStream closes the watcher resources and removes it
-func (w *watchGrpcStream) closeStream(ws *watcherStream) {
+func (w *watchGrpcStream) closeStream(ws *watcherStream) bool {
 	w.mu.Lock()
 	// cancels request stream; subscriber receives nil channel
 	close(ws.initReq.retc)
 	// close subscriber's channel
 	close(ws.outc)
 	delete(w.streams, ws.id)
+	empty := len(w.streams) == 0
+	if empty && w.stopc != nil {
+		w.stopc = nil
+	}
 	w.mu.Unlock()
+	return empty
 }
 
 // run is the root of the goroutines for managing a watcher client
@@ -464,6 +470,10 @@ func (w *watchGrpcStream) run() {
 			cancelSet = make(map[int64]struct{})
 		case <-stopc:
 			return
+		case ws := <-w.closingc:
+			if w.closeStream(ws) {
+				return
+			}
 		}
 
 		// send failed; queue for retry
@@ -522,6 +532,15 @@ func (w *watchGrpcStream) serveWatchClient(wc pb.Watch_WatchClient) {
 
 // serveStream forwards watch responses from run() to the subscriber
 func (w *watchGrpcStream) serveStream(ws *watcherStream) {
+	defer func() {
+		// signal that this watcherStream is finished
+		select {
+		case w.closingc <- ws:
+		case <-w.donec:
+			w.closeStream(ws)
+		}
+	}()
+
 	var closeErr error
 	emptyWr := &WatchResponse{}
 	wrs := []*WatchResponse{}
@@ -602,20 +621,9 @@ func (w *watchGrpcStream) serveStream(ws *watcherStream) {
 		}
 	}
 
-	w.closeStream(ws)
-	w.stopIfEmpty()
 	// lazily send cancel message if events on missing id
 }
 
-func (wgs *watchGrpcStream) stopIfEmpty() {
-	wgs.mu.Lock()
-	if len(wgs.streams) == 0 && wgs.stopc != nil {
-		close(wgs.stopc)
-		wgs.stopc = nil
-	}
-	wgs.mu.Unlock()
-}
-
 func (w *watchGrpcStream) newWatchClient() (pb.Watch_WatchClient, error) {
 	ws, rerr := w.resume()
 	if rerr != nil {
@@ -669,6 +677,10 @@ func (w *watchGrpcStream) resumeWatchers(wc pb.Watch_WatchClient) error {
 	w.mu.RUnlock()
 
 	for _, ws := range streams {
+		// drain recvc so no old WatchResponses (e.g., Created messages)
+		// are processed while resuming
+		ws.drain()
+
 		// pause serveStream
 		ws.resumec <- -1
 
@@ -701,6 +713,17 @@ func (w *watchGrpcStream) resumeWatchers(wc pb.Watch_WatchClient) error {
 	return nil
 }
 
+// drain removes all buffered WatchResponses from the stream's receive channel.
+func (ws *watcherStream) drain() {
+	for {
+		select {
+		case <-ws.recvc:
+		default:
+			return
+		}
+	}
+}
+
 // toPB converts an internal watch request structure to its protobuf messagefunc (wr *watchRequest)
 func (wr *watchRequest) toPB() *pb.WatchRequest {
 	req := &pb.WatchCreateRequest{

e2e/ctl_v3_txn_test.go

@@ -39,15 +39,23 @@ func txnTestSuccess(cx ctlCtx) {
 	if err := ctlV3Put(cx, "key2", "value2", ""); err != nil {
 		cx.t.Fatalf("txnTestSuccess ctlV3Put error (%v)", err)
 	}
-
-	rqs := txnRequests{
-		compare:  []string{`version("key1") = "1"`, `version("key2") = "1"`},
-		ifSucess: []string{"get key1", "get key2"},
-		ifFail:   []string{`put key1 "fail"`, `put key2 "fail"`},
-		results:  []string{"SUCCESS", "key1", "value1", "key2", "value2"},
+	rqs := []txnRequests{
+		{
+			compare:  []string{`version("key1") = "1"`, `version("key2") = "1"`},
+			ifSucess: []string{"get key1", "get key2", `put "key \"with\" space" "value \x23"`},
+			ifFail:   []string{`put key1 "fail"`, `put key2 "fail"`},
+			results:  []string{"SUCCESS", "key1", "value1", "key2", "value2"},
+		},
+		{
+			compare:  []string{`version("key \"with\" space") = "1"`},
+			ifSucess: []string{`get "key \"with\" space"`},
+			results:  []string{"SUCCESS", `key "with" space`, "value \x23"},
+		},
 	}
-	if err := ctlV3Txn(cx, rqs); err != nil {
-		cx.t.Fatal(err)
+	for _, rq := range rqs {
+		if err := ctlV3Txn(cx, rq); err != nil {
+			cx.t.Fatal(err)
+		}
 	}
 }
 

etcdctl/ctlv3/command/global.go

@@ -243,7 +243,7 @@ func authCfgFromCmd(cmd *cobra.Command) *authCfg {
 	var cfg authCfg
 
 	splitted := strings.SplitN(userFlag, ":", 2)
-	if len(splitted) == 0 {
+	if len(splitted) < 2 {
 		cfg.username = userFlag
 		cfg.password, err = speakeasy.Ask("Password: ")
 		if err != nil {

etcdctl/ctlv3/command/snapshot_command.go

@@ -36,7 +36,10 @@ import (
 	"github.com/coreos/etcd/pkg/types"
 	"github.com/coreos/etcd/raft"
 	"github.com/coreos/etcd/raft/raftpb"
+	"github.com/coreos/etcd/snap"
+	"github.com/coreos/etcd/store"
 	"github.com/coreos/etcd/wal"
+	"github.com/coreos/etcd/wal/walpb"
 	"github.com/spf13/cobra"
 	"golang.org/x/net/context"
 )
@@ -112,7 +115,7 @@ func snapshotSaveCommandFunc(cmd *cobra.Command, args []string) {
 
 	partpath := path + ".part"
 	f, err := os.Create(partpath)
-	defer f.Close()
+
 	if err != nil {
 		exiterr := fmt.Errorf("could not open %s (%v)", partpath, err)
 		ExitWithError(ExitBadArgs, exiterr)
@@ -131,6 +134,8 @@ func snapshotSaveCommandFunc(cmd *cobra.Command, args []string) {
 
 	fileutil.Fsync(f)
 
+	f.Close()
+
 	if rerr := os.Rename(partpath, path); rerr != nil {
 		exiterr := fmt.Errorf("could not rename %s to %s (%v)", partpath, path, rerr)
 		ExitWithError(ExitIO, exiterr)
@@ -186,8 +191,8 @@ func snapshotRestoreCommandFunc(cmd *cobra.Command, args []string) {
 		ExitWithError(ExitInvalidInput, fmt.Errorf("data-dir %q exists", basedir))
 	}
 
-	makeDB(snapdir, args[0])
-	makeWAL(waldir, cl)
+	makeDB(snapdir, args[0], len(cl.Members()))
+	makeWALAndSnap(waldir, snapdir, cl)
 }
 
 func initialClusterFromName(name string) string {
@@ -199,11 +204,18 @@ func initialClusterFromName(name string) string {
 }
 
 // makeWAL creates a WAL for the initial cluster
-func makeWAL(waldir string, cl *membership.RaftCluster) {
+func makeWALAndSnap(waldir, snapdir string, cl *membership.RaftCluster) {
 	if err := fileutil.CreateDirAll(waldir); err != nil {
 		ExitWithError(ExitIO, err)
 	}
 
+	// add members again to persist them to the store we create.
+	st := store.New(etcdserver.StoreClusterPrefix, etcdserver.StoreKeysPrefix)
+	cl.SetStore(st)
+	for _, m := range cl.Members() {
+		cl.AddMember(m)
+	}
+
 	m := cl.MemberByName(restoreName)
 	md := &etcdserverpb.Metadata{NodeID: uint64(m.ID), ClusterID: uint64(cl.ID())}
 	metadata, merr := md.Marshal()
@@ -227,7 +239,9 @@ func makeWAL(waldir string, cl *membership.RaftCluster) {
 	}
 
 	ents := make([]raftpb.Entry, len(peers))
+	nodeIDs := make([]uint64, len(peers))
 	for i, p := range peers {
+		nodeIDs[i] = p.ID
 		cc := raftpb.ConfChange{
 			Type:    raftpb.ConfChangeAddNode,
 			NodeID:  p.ID,
@@ -245,20 +259,48 @@ func makeWAL(waldir string, cl *membership.RaftCluster) {
 		ents[i] = e
 	}
 
-	w.Save(raftpb.HardState{
-		Term:   1,
+	commit, term := uint64(len(ents)), uint64(1)
+
+	if err := w.Save(raftpb.HardState{
+		Term:   term,
 		Vote:   peers[0].ID,
-		Commit: uint64(len(ents))}, ents)
+		Commit: commit}, ents); err != nil {
+		ExitWithError(ExitIO, err)
+	}
+
+	b, berr := st.Save()
+	if berr != nil {
+		ExitWithError(ExitError, berr)
+	}
+
+	raftSnap := raftpb.Snapshot{
+		Data: b,
+		Metadata: raftpb.SnapshotMetadata{
+			Index: commit,
+			Term:  term,
+			ConfState: raftpb.ConfState{
+				Nodes: nodeIDs,
+			},
+		},
+	}
+	snapshotter := snap.New(snapdir)
+	if err := snapshotter.SaveSnap(raftSnap); err != nil {
+		panic(err)
+	}
+
+	if err := w.SaveSnapshot(walpb.Snapshot{Index: commit, Term: term}); err != nil {
+		ExitWithError(ExitIO, err)
+	}
 }
 
 // initIndex implements ConsistentIndexGetter so the snapshot won't block
 // the new raft instance by waiting for a future raft index.
-type initIndex struct{}
+type initIndex int
 
-func (*initIndex) ConsistentIndex() uint64 { return 1 }
+func (i *initIndex) ConsistentIndex() uint64 { return uint64(*i) }
 
 // makeDB copies the database snapshot to the snapshot directory
-func makeDB(snapdir, dbfile string) {
+func makeDB(snapdir, dbfile string, commit int) {
 	f, ferr := os.OpenFile(dbfile, os.O_RDONLY, 0600)
 	if ferr != nil {
 		ExitWithError(ExitInvalidInput, ferr)
@@ -329,7 +371,7 @@ func makeDB(snapdir, dbfile string) {
 	// update consistentIndex so applies go through on etcdserver despite
 	// having a new raft instance
 	be := backend.NewDefaultBackend(dbpath)
-	s := mvcc.NewStore(be, nil, &initIndex{})
+	s := mvcc.NewStore(be, nil, (*initIndex)(&commit))
 	id := s.TxnBegin()
 	btx := be.BatchTx()
 	del := func(k, v []byte) error {
@@ -339,6 +381,7 @@ func makeDB(snapdir, dbfile string) {
 
 	// delete stored members from old cluster since using new members
 	btx.UnsafeForEach([]byte("members"), del)
+	// todo: add back new members when we start to deprecate old snap file.
 	btx.UnsafeForEach([]byte("members_removed"), del)
 	// trigger write-out of new consistent index
 	s.TxnEnd(id)

etcdctl/ctlv3/command/txn_command.go

@@ -77,12 +77,13 @@ func readCompares(r *bufio.Reader) (cmps []clientv3.Cmp) {
 		if err != nil {
 			ExitWithError(ExitInvalidInput, err)
 		}
-		if len(line) == 1 {
+
+		// remove space from the line
+		line = strings.TrimSpace(line)
+		if len(line) == 0 {
 			break
 		}
 
-		// remove trialling \n
-		line = line[:len(line)-1]
 		cmp, err := parseCompare(line)
 		if err != nil {
 			ExitWithError(ExitInvalidInput, err)
@@ -99,12 +100,13 @@ func readOps(r *bufio.Reader) (ops []clientv3.Op) {
 		if err != nil {
 			ExitWithError(ExitInvalidInput, err)
 		}
-		if len(line) == 1 {
+
+		// remove space from the line
+		line = strings.TrimSpace(line)
+		if len(line) == 0 {
 			break
 		}
 
-		// remove trialling \n
-		line = line[:len(line)-1]
 		op, err := parseRequestUnion(line)
 		if err != nil {
 			ExitWithError(ExitInvalidInput, err)

etcdctl/ctlv3/command/util.go

@@ -46,8 +46,23 @@ func addHexPrefix(s string) string {
 }
 
 func argify(s string) []string {
-	r := regexp.MustCompile("'.+'|\".+\"|\\S+")
-	return r.FindAllString(s, -1)
+	r := regexp.MustCompile(`"(?:[^"\\]|\\.)*"|'[^']*'|[^'"\s]\S*[^'"\s]?`)
+	args := r.FindAllString(s, -1)
+	for i := range args {
+		if len(args[i]) == 0 {
+			continue
+		}
+		if args[i][0] == '\'' {
+			// 'single-quoted string'
+			args[i] = args[i][1 : len(args)-1]
+		} else if args[i][0] == '"' {
+			// "double quoted string"
+			if _, err := fmt.Sscanf(args[i], "%q", &args[i]); err != nil {
+				ExitWithError(ExitInvalidInput, err)
+			}
+		}
+	}
+	return args
 }
 
 func commandCtx(cmd *cobra.Command) (context.Context, context.CancelFunc) {

etcdctl/ctlv3/command/watch_command.go

@@ -52,30 +52,18 @@ func watchCommandFunc(cmd *cobra.Command, args []string) {
 		watchInteractiveFunc(cmd, args)
 		return
 	}
-	if len(args) < 1 || len(args) > 2 {
-		ExitWithError(ExitBadArgs, fmt.Errorf("watch in non-interactive mode requires one or two arguments as key or prefix, with range end"))
-	}
 
-	opts := []clientv3.OpOption{clientv3.WithRev(watchRev)}
-	key := args[0]
-	if len(args) == 2 {
-		if watchPrefix {
-			ExitWithError(ExitBadArgs, fmt.Errorf("`range_end` and `--prefix` cannot be set at the same time, choose one"))
-		}
-		opts = append(opts, clientv3.WithRange(args[1]))
-	}
-
-	if watchPrefix {
-		opts = append(opts, clientv3.WithPrefix())
-	}
 	c := mustClientFromCmd(cmd)
-	wc := c.Watch(context.TODO(), key, opts...)
-	printWatchCh(wc)
-	err := c.Close()
-	if err == nil {
-		ExitWithError(ExitInterrupted, fmt.Errorf("watch is canceled by the server"))
+	wc, err := getWatchChan(c, args)
+	if err != nil {
+		ExitWithError(ExitBadArgs, err)
 	}
-	ExitWithError(ExitBadConnection, err)
+
+	printWatchCh(wc)
+	if err = c.Close(); err != nil {
+		ExitWithError(ExitBadConnection, err)
+	}
+	ExitWithError(ExitInterrupted, fmt.Errorf("watch is canceled by the server"))
 }
 
 func watchInteractiveFunc(cmd *cobra.Command, args []string) {
@@ -107,32 +95,33 @@ func watchInteractiveFunc(cmd *cobra.Command, args []string) {
 			fmt.Fprintf(os.Stderr, "Invalid command %s (%v)\n", l, err)
 			continue
 		}
-		moreargs := flagset.Args()
-		if len(moreargs) < 1 || len(moreargs) > 2 {
-			fmt.Fprintf(os.Stderr, "Invalid command %s (Too few or many arguments)\n", l)
+		ch, err := getWatchChan(c, flagset.Args())
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Invalid command %s (%v)\n", l, err)
 			continue
 		}
-		var key string
-		_, err = fmt.Sscanf(moreargs[0], "%q", &key)
-		if err != nil {
-			key = moreargs[0]
-		}
-		opts := []clientv3.OpOption{clientv3.WithRev(watchRev)}
-		if len(moreargs) == 2 {
-			if watchPrefix {
-				fmt.Fprintf(os.Stderr, "`range_end` and `--prefix` cannot be set at the same time, choose one\n")
-				continue
-			}
-			opts = append(opts, clientv3.WithRange(moreargs[1]))
-		}
-		if watchPrefix {
-			opts = append(opts, clientv3.WithPrefix())
-		}
-		ch := c.Watch(context.TODO(), key, opts...)
 		go printWatchCh(ch)
 	}
 }
 
+func getWatchChan(c *clientv3.Client, args []string) (clientv3.WatchChan, error) {
+	if len(args) < 1 || len(args) > 2 {
+		return nil, fmt.Errorf("bad number of arguments")
+	}
+	key := args[0]
+	opts := []clientv3.OpOption{clientv3.WithRev(watchRev)}
+	if len(args) == 2 {
+		if watchPrefix {
+			return nil, fmt.Errorf("`range_end` and `--prefix` are mutually exclusive")
+		}
+		opts = append(opts, clientv3.WithRange(args[1]))
+	}
+	if watchPrefix {
+		opts = append(opts, clientv3.WithPrefix())
+	}
+	return c.Watch(context.TODO(), key, opts...), nil
+}
+
 func printWatchCh(ch clientv3.WatchChan) {
 	for resp := range ch {
 		display.Watch(resp)

etcdmain/config.go

@@ -20,6 +20,7 @@ import (
 	"flag"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/url"
 	"os"
 	"runtime"
@@ -410,6 +411,13 @@ func (cfg *config) configFromFile() error {
 }
 
 func (cfg *config) validateConfig(isSet func(field string) bool) error {
+	if err := checkBindURLs(cfg.lpurls); err != nil {
+		return err
+	}
+	if err := checkBindURLs(cfg.lcurls); err != nil {
+		return err
+	}
+
 	// when etcd runs in member mode user needs to set --advertise-client-urls if --listen-client-urls is set.
 	// TODO(yichengq): check this for joining through discovery service case
 	mayFallbackToProxy := isSet("discovery") && cfg.fallback.String() == fallbackFlagProxy
@@ -456,3 +464,27 @@ func (cfg config) isReadonlyProxy() bool       { return cfg.proxy.String() == pr
 func (cfg config) shouldFallbackToProxy() bool { return cfg.fallback.String() == fallbackFlagProxy }
 
 func (cfg config) electionTicks() int { return int(cfg.ElectionMs / cfg.TickMs) }
+
+// checkBindURLs returns an error if any URL uses a domain name.
+// TODO: return error in 3.2.0
+func checkBindURLs(urls []url.URL) error {
+	for _, url := range urls {
+		if url.Scheme == "unix" || url.Scheme == "unixs" {
+			continue
+		}
+		host, _, err := net.SplitHostPort(url.Host)
+		if err != nil {
+			return err
+		}
+		if host == "localhost" {
+			// special case for local address
+			// TODO: support /etc/hosts ?
+			continue
+		}
+		if net.ParseIP(host) == nil {
+			err := fmt.Errorf("expected IP in URL for binding (%s)", url.String())
+			plog.Warning(err)
+		}
+	}
+	return nil
+}

integration/v3_election_test.go

@@ -188,11 +188,8 @@ func TestElectionOnPrefixOfExistingKey(t *testing.T) {
 	if _, err := cli.Put(context.TODO(), "testa", "value"); err != nil {
 		t.Fatal(err)
 	}
-	s, serr := concurrency.NewSession(cli)
-	if serr != nil {
-		t.Fatal(serr)
-	}
-	e := concurrency.NewElection(s, "test")
+
+	e := concurrency.NewElection(cli, "test")
 	ctx, cancel := context.WithTimeout(context.TODO(), 5*time.Second)
 	err := e.Campaign(ctx, "abc")
 	cancel()

pkg/fileutil/dir_unix.go

@@ -0,0 +1,22 @@
+// Copyright 2016 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.
+
+// +build !windows
+
+package fileutil
+
+import "os"
+
+// OpenDir opens a directory for syncing.
+func OpenDir(path string) (*os.File, error) { return os.Open(path) }

pkg/fileutil/dir_windows.go

@@ -0,0 +1,46 @@
+// Copyright 2016 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.
+
+// +build windows
+
+package fileutil
+
+import (
+	"os"
+	"syscall"
+)
+
+// OpenDir opens a directory in windows with write access for syncing.
+func OpenDir(path string) (*os.File, error) {
+	fd, err := openDir(path)
+	if err != nil {
+		return nil, err
+	}
+	return os.NewFile(uintptr(fd), path), nil
+}
+
+func openDir(path string) (fd syscall.Handle, err error) {
+	if len(path) == 0 {
+		return syscall.InvalidHandle, syscall.ERROR_FILE_NOT_FOUND
+	}
+	pathp, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return syscall.InvalidHandle, err
+	}
+	access := uint32(syscall.GENERIC_READ | syscall.GENERIC_WRITE)
+	sharemode := uint32(syscall.FILE_SHARE_READ | syscall.FILE_SHARE_WRITE)
+	createmode := uint32(syscall.OPEN_EXISTING)
+	fl := uint32(syscall.FILE_FLAG_BACKUP_SEMANTICS)
+	return syscall.CreateFile(pathp, access, sharemode, nil, createmode, fl, 0)
+}

rafthttp/stream.go

@@ -49,6 +49,7 @@ var (
 		"2.1.0": {streamTypeMsgAppV2, streamTypeMessage},
 		"2.2.0": {streamTypeMsgAppV2, streamTypeMessage},
 		"2.3.0": {streamTypeMsgAppV2, streamTypeMessage},
+		"3.0.0": {streamTypeMsgAppV2, streamTypeMessage},
 	}
 )
 

version/version.go

@@ -29,7 +29,7 @@ import (
 var (
 	// MinClusterVersion is the min cluster version this etcd binary is compatible with.
 	MinClusterVersion = "2.3.0"
-	Version           = "3.0.7"
+	Version           = "3.0.10"
 
 	// Git SHA Value will be set during build
 	GitSHA = "Not provided (use ./build instead of go build)"

wal/wal.go

@@ -67,7 +67,11 @@ var (
 // A just opened WAL is in read mode, and ready for reading records.
 // The WAL will be ready for appending after reading out all the previous records.
 type WAL struct {
-	dir      string           // the living directory of the underlay files
+	dir string // the living directory of the underlay files
+
+	// dirFile is a fd for the wal directory for syncing on Rename
+	dirFile *os.File
+
 	metadata []byte           // metadata recorded at the head of each WAL
 	state    raftpb.HardState // hardstate recorded at the head of WAL
 
@@ -106,10 +110,10 @@ func Create(dirpath string, metadata []byte) (*WAL, error) {
 	if err != nil {
 		return nil, err
 	}
-	if _, err := f.Seek(0, os.SEEK_END); err != nil {
+	if _, err = f.Seek(0, os.SEEK_END); err != nil {
 		return nil, err
 	}
-	if err := fileutil.Preallocate(f.File, segmentSizeBytes, true); err != nil {
+	if err = fileutil.Preallocate(f.File, segmentSizeBytes, true); err != nil {
 		return nil, err
 	}
 
@@ -119,17 +123,33 @@ func Create(dirpath string, metadata []byte) (*WAL, error) {
 		encoder:  newEncoder(f, 0),
 	}
 	w.locks = append(w.locks, f)
-	if err := w.saveCrc(0); err != nil {
+	if err = w.saveCrc(0); err != nil {
 		return nil, err
 	}
-	if err := w.encoder.encode(&walpb.Record{Type: metadataType, Data: metadata}); err != nil {
+	if err = w.encoder.encode(&walpb.Record{Type: metadataType, Data: metadata}); err != nil {
 		return nil, err
 	}
-	if err := w.SaveSnapshot(walpb.Snapshot{}); err != nil {
+	if err = w.SaveSnapshot(walpb.Snapshot{}); err != nil {
 		return nil, err
 	}
 
-	return w.renameWal(tmpdirpath)
+	if w, err = w.renameWal(tmpdirpath); err != nil {
+		return nil, err
+	}
+
+	// directory was renamed; sync parent dir to persist rename
+	pdir, perr := fileutil.OpenDir(path.Dir(w.dir))
+	if perr != nil {
+		return nil, perr
+	}
+	if perr = fileutil.Fsync(pdir); perr != nil {
+		return nil, perr
+	}
+	if perr = pdir.Close(); err != nil {
+		return nil, perr
+	}
+
+	return w, nil
 }
 
 // Open opens the WAL at the given snap.
@@ -139,7 +159,14 @@ func Create(dirpath string, metadata []byte) (*WAL, error) {
 // the given snap. The WAL cannot be appended to before reading out all of its
 // previous records.
 func Open(dirpath string, snap walpb.Snapshot) (*WAL, error) {
-	return openAtIndex(dirpath, snap, true)
+	w, err := openAtIndex(dirpath, snap, true)
+	if err != nil {
+		return nil, err
+	}
+	if w.dirFile, err = fileutil.OpenDir(w.dir); err != nil {
+		return nil, err
+	}
+	return w, nil
 }
 
 // OpenForRead only opens the wal files for read.
@@ -371,6 +398,10 @@ func (w *WAL) cut() error {
 	if err = os.Rename(newTail.Name(), fpath); err != nil {
 		return err
 	}
+	if err = fileutil.Fsync(w.dirFile); err != nil {
+		return err
+	}
+
 	newTail.Close()
 
 	if newTail, err = fileutil.LockFile(fpath, os.O_WRONLY, fileutil.PrivateFileMode); err != nil {
@@ -473,7 +504,7 @@ func (w *WAL) Close() error {
 			plog.Errorf("failed to unlock during closing wal: %s", err)
 		}
 	}
-	return nil
+	return w.dirFile.Close()
 }
 
 func (w *WAL) saveEntry(e *raftpb.Entry) error {

wal/wal_unix.go

@@ -16,7 +16,11 @@
 
 package wal
 
-import "os"
+import (
+	"os"
+
+	"github.com/coreos/etcd/pkg/fileutil"
+)
 
 func (w *WAL) renameWal(tmpdirpath string) (*WAL, error) {
 	// On non-Windows platforms, hold the lock while renaming. Releasing
@@ -34,5 +38,7 @@ func (w *WAL) renameWal(tmpdirpath string) (*WAL, error) {
 	}
 
 	w.fp = newFilePipeline(w.dir, segmentSizeBytes)
-	return w, nil
+	df, err := fileutil.OpenDir(w.dir)
+	w.dirFile = df
+	return w, err
 }