Merge branch 'master' into update

server/embed/config_logging.go

@@ -40,6 +40,26 @@ func (cfg Config) GetLogger() *zap.Logger {
 // for testing
 var grpcLogOnce = new(sync.Once)
 
+func setupGrpcLogging(debug bool, config zap.Config) {
+	grpcLogOnce.Do(func() {
+		// debug true, enable info, warning, error
+		// debug false, only discard info
+		if debug {
+			var gl grpclog.LoggerV2
+			gl, err := logutil.NewGRPCLoggerV2(config)
+			if err == nil {
+				grpclog.SetLoggerV2(gl)
+			}
+		} else {
+			grpclog.SetLoggerV2(grpclog.NewLoggerV2(ioutil.Discard, os.Stderr, os.Stderr))
+		}
+	})
+}
+
+func SetupGrpcLoggingForTest(debug bool) {
+	setupGrpcLogging(debug, zap.NewDevelopmentConfig())
+}
+
 // setupLogging initializes etcd logging.
 // Must be called after flag parsing or finishing configuring embed.Config.
 func (cfg *Config) setupLogging() error {
@@ -106,19 +126,7 @@ func (cfg *Config) setupLogging() error {
 					c.loggerConfig = &copied
 					c.loggerCore = nil
 					c.loggerWriteSyncer = nil
-					grpcLogOnce.Do(func() {
-						// debug true, enable info, warning, error
-						// debug false, only discard info
-						if cfg.LogLevel == "debug" {
-							var gl grpclog.LoggerV2
-							gl, err = logutil.NewGRPCLoggerV2(copied)
-							if err == nil {
-								grpclog.SetLoggerV2(gl)
-							}
-						} else {
-							grpclog.SetLoggerV2(grpclog.NewLoggerV2(ioutil.Discard, os.Stderr, os.Stderr))
-						}
-					})
+					setupGrpcLogging(cfg.LogLevel == "debug", copied)
 					return nil
 				}
 			}

server/etcdserver/api/membership/cluster.go

@@ -556,7 +556,7 @@ func (c *RaftCluster) IsReadyToAddVotingMember() bool {
 
 	if nstarted == 1 && nmembers == 2 {
 		// a case of adding a new node to 1-member cluster for restoring cluster data
-		// https://github.com/etcd-io/etcd/blob/master/Documentation/v2/admin_guide.md#restoring-the-cluster
+		// https://github.com/etcd-io/website/blob/master/content/docs/v2/admin_guide.md#restoring-the-cluster
 		c.lg.Debug("number of started member is 1; can accept add member request")
 		return true
 	}

server/etcdserver/api/v2error/error.go

@@ -13,7 +13,8 @@
 // limitations under the License.
 
 // Package v2error describes errors in etcd project. When any change happens,
-// Documentation/v2/errorcode.md needs to be updated correspondingly.
+// https://github.com/etcd-io/website/blob/master/content/docs/v2/errorcode.md
+// needs to be updated correspondingly.
 // To be deprecated in favor of v3 APIs.
 package v2error
 

server/etcdserver/api/v2store/node_extern_test.go

@@ -18,7 +18,6 @@ import (
 	"reflect"
 	"testing"
 	"time"
-	"unsafe"
 
 	"go.etcd.io/etcd/pkg/v3/testutil"
 )
@@ -102,7 +101,7 @@ func TestNodeExternClone(t *testing.T) {
 }
 
 func sameSlice(a, b []*NodeExtern) bool {
-	ah := (*reflect.SliceHeader)(unsafe.Pointer(&a))
-	bh := (*reflect.SliceHeader)(unsafe.Pointer(&b))
-	return *ah == *bh
+	va := reflect.ValueOf(a)
+	vb := reflect.ValueOf(b)
+	return va.Len() == vb.Len() && va.Pointer() == vb.Pointer()
 }

server/etcdserver/api/v3election/v3electionpb/gw/v3election.pb.gw.go

@@ -1,5 +1,5 @@
 // Code generated by protoc-gen-grpc-gateway. DO NOT EDIT.
-// source: etcdserver/api/v3election/v3electionpb/v3election.proto
+// source: server/etcdserver/api/v3election/v3electionpb/v3election.proto
 
 /*
 Package v3electionpb is a reverse proxy.

server/etcdserver/api/v3lock/v3lockpb/gw/v3lock.pb.gw.go

@@ -1,5 +1,5 @@
 // Code generated by protoc-gen-grpc-gateway. DO NOT EDIT.
-// source: etcdserver/api/v3lock/v3lockpb/v3lock.proto
+// source: server/etcdserver/api/v3lock/v3lockpb/v3lock.proto
 
 /*
 Package v3lockpb is a reverse proxy.

server/wal/wal.go

@@ -419,6 +419,13 @@ func openWALFiles(lg *zap.Logger, dirpath string, names []string, nameIndex int,
 // TODO: detect not-last-snap error.
 // TODO: maybe loose the checking of match.
 // After ReadAll, the WAL will be ready for appending new records.
+//
+// ReadAll suppresses WAL entries that got overridden (i.e. a newer entry with the same index
+// exists in the log). Such a situation can happen in cases described in figure 7. of the
+// RAFT paper (http://web.stanford.edu/~ouster/cgi-bin/papers/raft-atc14.pdf).
+//
+// ReadAll may return uncommitted yet entries, that are subject to be overriden.
+// Do not apply entries that have index > state.commit, as they are subject to change.
 func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.Entry, err error) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
@@ -443,6 +450,7 @@ func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.
 					// return error before append call causes runtime panic
 					return nil, state, nil, ErrSliceOutOfRange
 				}
+				// The line below is potentially overriding some 'uncommitted' entries.
 				ents = append(ents[:up], e)
 			}
 			w.enti = e.Index