Merge pull request #2460 from xiang90/raft-logger

raft: introduce logger interface

raft/log.go

@@ -77,7 +77,7 @@ func (l *raftLog) maybeAppend(index, logTerm, committed uint64, ents ...pb.Entry
 		switch {
 		case ci == 0:
 		case ci <= l.committed:
-			log.Panicf("entry %d conflict with committed entry [committed(%d)]", ci, l.committed)
+			raftLogger.Panicf("entry %d conflict with committed entry [committed(%d)]", ci, l.committed)
 		default:
 			offset := index + 1
 			l.append(ents[ci-offset:]...)
@@ -93,7 +93,7 @@ func (l *raftLog) append(ents ...pb.Entry) uint64 {
 		return l.lastIndex()
 	}
 	if after := ents[0].Index - 1; after < l.committed {
-		log.Panicf("after(%d) is out of range [committed(%d)]", after, l.committed)
+		raftLogger.Panicf("after(%d) is out of range [committed(%d)]", after, l.committed)
 	}
 	l.unstable.truncateAndAppend(ents)
 	return l.lastIndex()
@@ -114,7 +114,7 @@ func (l *raftLog) findConflict(ents []pb.Entry) uint64 {
 	for _, ne := range ents {
 		if !l.matchTerm(ne.Index, ne.Term) {
 			if ne.Index <= l.lastIndex() {
-				log.Printf("raftlog: found conflict at index %d [existing term: %d, conflicting term: %d]",
+				raftLogger.Infof("raftlog: found conflict at index %d [existing term: %d, conflicting term: %d]",
 					ne.Index, l.term(ne.Index), ne.Term)
 			}
 			return ne.Index
@@ -174,7 +174,7 @@ func (l *raftLog) commitTo(tocommit uint64) {
 	// never decrease commit
 	if l.committed < tocommit {
 		if l.lastIndex() < tocommit {
-			log.Panicf("tocommit(%d) is out of range [lastIndex(%d)]", tocommit, l.lastIndex())
+			raftLogger.Panicf("tocommit(%d) is out of range [lastIndex(%d)]", tocommit, l.lastIndex())
 		}
 		l.committed = tocommit
 	}
@@ -185,7 +185,7 @@ func (l *raftLog) appliedTo(i uint64) {
 		return
 	}
 	if l.committed < i || i < l.applied {
-		log.Panicf("applied(%d) is out of range [prevApplied(%d), committed(%d)]", i, l.applied, l.committed)
+		raftLogger.Panicf("applied(%d) is out of range [prevApplied(%d), committed(%d)]", i, l.applied, l.committed)
 	}
 	l.applied = i
 }
@@ -248,7 +248,7 @@ func (l *raftLog) maybeCommit(maxIndex, term uint64) bool {
 }
 
 func (l *raftLog) restore(s pb.Snapshot) {
-	log.Printf("raftlog: log [%s] starts to restore snapshot [index: %d, term: %d]", l, s.Metadata.Index, s.Metadata.Term)
+	raftLogger.Infof("raftlog: log [%s] starts to restore snapshot [index: %d, term: %d]", l, s.Metadata.Index, s.Metadata.Term)
 	l.committed = s.Metadata.Index
 	l.unstable.restore(s)
 }
@@ -264,9 +264,9 @@ func (l *raftLog) slice(lo uint64, hi uint64) []pb.Entry {
 		storedEnts, err := l.storage.Entries(lo, min(hi, l.unstable.offset))
 		if err == ErrCompacted {
 			// This should never fail because it has been checked before.
-			log.Panicf("entries[%d:%d) from storage is out of bound", lo, min(hi, l.unstable.offset))
+			raftLogger.Panicf("entries[%d:%d) from storage is out of bound", lo, min(hi, l.unstable.offset))
 		} else if err == ErrUnavailable {
-			log.Panicf("entries[%d:%d) is unavailable from storage", lo, min(hi, l.unstable.offset))
+			raftLogger.Panicf("entries[%d:%d) is unavailable from storage", lo, min(hi, l.unstable.offset))
 		} else if err != nil {
 			panic(err) // TODO(bdarnell)
 		}
@@ -287,10 +287,10 @@ func (l *raftLog) slice(lo uint64, hi uint64) []pb.Entry {
 // l.firstIndex <= lo <= hi <= l.firstIndex + len(l.entries)
 func (l *raftLog) mustCheckOutOfBounds(lo, hi uint64) {
 	if lo > hi {
-		log.Panicf("raft: invalid slice %d > %d", lo, hi)
+		raftLogger.Panicf("raft: invalid slice %d > %d", lo, hi)
 	}
 	length := l.lastIndex() - l.firstIndex() + 1
 	if lo < l.firstIndex() || hi > l.firstIndex()+length {
-		log.Panicf("raft: slice[%d,%d) out of bound [%d,%d]", lo, hi, l.firstIndex(), l.lastIndex())
+		raftLogger.Panicf("raft: slice[%d,%d) out of bound [%d,%d]", lo, hi, l.firstIndex(), l.lastIndex())
 	}
 }

raft/log_unstable.go

@@ -14,11 +14,7 @@
 
 package raft
 
-import (
-	"log"
-
-	pb "github.com/coreos/etcd/raft/raftpb"
-)
+import pb "github.com/coreos/etcd/raft/raftpb"
 
 // unstable.entris[i] has raft log position i+unstable.offset.
 // Note that unstable.offset may be less than the highest log
@@ -110,7 +106,7 @@ func (u *unstable) truncateAndAppend(ents []pb.Entry) {
 		// directly append
 		u.entries = append(u.entries, ents...)
 	case after < u.offset:
-		log.Printf("raftlog: replace the unstable entries from index %d", after+1)
+		raftLogger.Infof("raftlog: replace the unstable entries from index %d", after+1)
 		// The log is being truncated to before our current offset
 		// portion, so set the offset and replace the entries
 		u.offset = after + 1
@@ -118,7 +114,7 @@ func (u *unstable) truncateAndAppend(ents []pb.Entry) {
 	default:
 		// truncate to after and copy to u.entries
 		// then append
-		log.Printf("raftlog: truncate the unstable entries to index %d", after)
+		raftLogger.Infof("raftlog: truncate the unstable entries to index %d", after)
 		u.entries = append([]pb.Entry{}, u.slice(u.offset, after+1)...)
 		u.entries = append(u.entries, ents...)
 	}
@@ -132,10 +128,10 @@ func (u *unstable) slice(lo uint64, hi uint64) []pb.Entry {
 // u.offset <= lo <= hi <= u.offset+len(u.offset)
 func (u *unstable) mustCheckOutOfBounds(lo, hi uint64) {
 	if lo > hi {
-		log.Panicf("raft: invalid unstable.slice %d > %d", lo, hi)
+		raftLogger.Panicf("raft: invalid unstable.slice %d > %d", lo, hi)
 	}
 	upper := u.offset + uint64(len(u.entries))
 	if lo < u.offset || hi > upper {
-		log.Panicf("raft: unstable.slice[%d,%d) out of bound [%d,%d]", lo, hi, u.offset, upper)
+		raftLogger.Panicf("raft: unstable.slice[%d,%d) out of bound [%d,%d]", lo, hi, u.offset, upper)
 	}
 }

raft/logger.go

@@ -0,0 +1,126 @@
+// Copyright 2015 CoreOS, Inc.
+//
+// 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
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+)
+
+type Logger interface {
+	Debug(v ...interface{})
+	Debugf(format string, v ...interface{})
+
+	Error(v ...interface{})
+	Errorf(format string, v ...interface{})
+
+	Info(v ...interface{})
+	Infof(format string, v ...interface{})
+
+	Warning(v ...interface{})
+	Warningf(format string, v ...interface{})
+
+	Fatal(v ...interface{})
+	Fatalf(format string, v ...interface{})
+
+	Panic(v ...interface{})
+	Panicf(format string, v ...interface{})
+}
+
+func SetLogger(l Logger) { raftLogger = l }
+
+var (
+	defaultLogger = &DefaultLogger{Logger: log.New(os.Stderr, "", 0)}
+	discardLogger = &DefaultLogger{Logger: log.New(ioutil.Discard, "", 0)}
+	raftLogger    = Logger(defaultLogger)
+)
+
+const (
+	calldepth = 2
+)
+
+// DefaultLogger is a defualt implementation of the Logger interface.
+type DefaultLogger struct {
+	*log.Logger
+	debug bool
+}
+
+func (l *DefaultLogger) EnableTimestamps() {
+	l.SetFlags(l.Flags() | log.Ldate | log.Ltime)
+}
+
+func (l *DefaultLogger) EnableDebug() {
+	l.debug = true
+}
+
+func (l *DefaultLogger) Debug(v ...interface{}) {
+	if l.debug {
+		l.Output(calldepth, header("DEBUG", fmt.Sprint(v...)))
+	}
+}
+
+func (l *DefaultLogger) Debugf(format string, v ...interface{}) {
+	if l.debug {
+		l.Output(calldepth, header("DEBUG", fmt.Sprintf(format, v...)))
+	}
+}
+
+func (l *DefaultLogger) Info(v ...interface{}) {
+	l.Output(calldepth, header("INFO", fmt.Sprint(v...)))
+}
+
+func (l *DefaultLogger) Infof(format string, v ...interface{}) {
+	l.Output(calldepth, header("INFO", fmt.Sprintf(format, v...)))
+}
+
+func (l *DefaultLogger) Error(v ...interface{}) {
+	l.Output(calldepth, header("ERROR", fmt.Sprint(v...)))
+}
+
+func (l *DefaultLogger) Errorf(format string, v ...interface{}) {
+	l.Output(calldepth, header("ERROR", fmt.Sprintf(format, v...)))
+}
+
+func (l *DefaultLogger) Warning(v ...interface{}) {
+	l.Output(calldepth, header("WARN", fmt.Sprint(v...)))
+}
+
+func (l *DefaultLogger) Warningf(format string, v ...interface{}) {
+	l.Output(calldepth, header("WARN", fmt.Sprintf(format, v...)))
+}
+
+func (l *DefaultLogger) Fatal(v ...interface{}) {
+	l.Output(calldepth, header("FATAL", fmt.Sprint(v...)))
+	os.Exit(1)
+}
+
+func (l *DefaultLogger) Fatalf(format string, v ...interface{}) {
+	l.Output(calldepth, header("FATAL", fmt.Sprintf(format, v...)))
+	os.Exit(1)
+}
+
+func (l *DefaultLogger) Panic(v ...interface{}) {
+	l.Logger.Panic(v)
+}
+
+func (l *DefaultLogger) Panicf(format string, v ...interface{}) {
+	l.Logger.Panicf(format, v)
+}
+
+func header(lvl, msg string) string {
+	return fmt.Sprintf("%s: %s", lvl, msg)
+}

raft/node.go

@@ -16,7 +16,6 @@ package raft
 
 import (
 	"errors"
-	"log"
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
 	pb "github.com/coreos/etcd/raft/raftpb"
@@ -263,13 +262,13 @@ func (n *node) run(r *raft) {
 		if lead != r.lead {
 			if r.hasLeader() {
 				if lead == None {
-					log.Printf("raft.node: %x elected leader %x at term %d", r.id, r.lead, r.Term)
+					raftLogger.Infof("raft.node: %x elected leader %x at term %d", r.id, r.lead, r.Term)
 				} else {
-					log.Printf("raft.node: %x changed leader from %x to %x at term %d", r.id, lead, r.lead, r.Term)
+					raftLogger.Infof("raft.node: %x changed leader from %x to %x at term %d", r.id, lead, r.lead, r.Term)
 				}
 				propc = n.propc
 			} else {
-				log.Printf("raft.node: %x lost leader %x at term %d", r.id, lead, r.Term)
+				raftLogger.Infof("raft.node: %x lost leader %x at term %d", r.id, lead, r.Term)
 				propc = nil
 			}
 			lead = r.lead

raft/raft.go

@@ -17,7 +17,6 @@ package raft
 import (
 	"errors"
 	"fmt"
-	"log"
 	"math/rand"
 	"sort"
 	"strings"
@@ -229,7 +228,7 @@ func newRaft(id uint64, peers []uint64, election, heartbeat int, storage Storage
 		nodesStrs = append(nodesStrs, fmt.Sprintf("%x", n))
 	}
 
-	log.Printf("raft: newRaft %x [peers: [%s], term: %d, commit: %d, applied: %d, lastindex: %d, lastterm: %d]",
+	raftLogger.Infof("raft: newRaft %x [peers: [%s], term: %d, commit: %d, applied: %d, lastindex: %d, lastterm: %d]",
 		r.id, strings.Join(nodesStrs, ","), r.Term, r.raftLog.committed, r.raftLog.applied, r.raftLog.lastIndex(), r.raftLog.lastTerm())
 	return r
 }
@@ -286,10 +285,10 @@ func (r *raft) sendAppend(to uint64) {
 		}
 		m.Snapshot = snapshot
 		sindex, sterm := snapshot.Metadata.Index, snapshot.Metadata.Term
-		log.Printf("raft: %x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
+		raftLogger.Infof("raft: %x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
 			r.id, r.raftLog.firstIndex(), r.Commit, sindex, sterm, to, pr)
 		pr.setPendingSnapshot(sindex)
-		log.Printf("raft: %x paused sending replication messages to %x [%s]", r.id, to, pr)
+		raftLogger.Infof("raft: %x paused sending replication messages to %x [%s]", r.id, to, pr)
 	} else {
 		m.Type = pb.MsgApp
 		m.Index = pr.Next - 1
@@ -413,7 +412,7 @@ func (r *raft) becomeFollower(term uint64, lead uint64) {
 	r.tick = r.tickElection
 	r.lead = lead
 	r.state = StateFollower
-	log.Printf("raft: %x became follower at term %d", r.id, r.Term)
+	raftLogger.Infof("raft: %x became follower at term %d", r.id, r.Term)
 }
 
 func (r *raft) becomeCandidate() {
@@ -426,7 +425,7 @@ func (r *raft) becomeCandidate() {
 	r.tick = r.tickElection
 	r.Vote = r.id
 	r.state = StateCandidate
-	log.Printf("raft: %x became candidate at term %d", r.id, r.Term)
+	raftLogger.Infof("raft: %x became candidate at term %d", r.id, r.Term)
 }
 
 func (r *raft) becomeLeader() {
@@ -449,7 +448,7 @@ func (r *raft) becomeLeader() {
 		r.pendingConf = true
 	}
 	r.appendEntry(pb.Entry{Data: nil})
-	log.Printf("raft: %x became leader at term %d", r.id, r.Term)
+	raftLogger.Infof("raft: %x became leader at term %d", r.id, r.Term)
 }
 
 func (r *raft) campaign() {
@@ -462,7 +461,7 @@ func (r *raft) campaign() {
 		if i == r.id {
 			continue
 		}
-		log.Printf("raft: %x [logterm: %d, index: %d] sent vote request to %x at term %d",
+		raftLogger.Infof("raft: %x [logterm: %d, index: %d] sent vote request to %x at term %d",
 			r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), i, r.Term)
 		r.send(pb.Message{To: i, Type: pb.MsgVote, Index: r.raftLog.lastIndex(), LogTerm: r.raftLog.lastTerm()})
 	}
@@ -470,9 +469,9 @@ func (r *raft) campaign() {
 
 func (r *raft) poll(id uint64, v bool) (granted int) {
 	if v {
-		log.Printf("raft: %x received vote from %x at term %d", r.id, id, r.Term)
+		raftLogger.Infof("raft: %x received vote from %x at term %d", r.id, id, r.Term)
 	} else {
-		log.Printf("raft: %x received vote rejection from %x at term %d", r.id, id, r.Term)
+		raftLogger.Infof("raft: %x received vote rejection from %x at term %d", r.id, id, r.Term)
 	}
 	if _, ok := r.votes[id]; !ok {
 		r.votes[id] = v
@@ -487,7 +486,7 @@ func (r *raft) poll(id uint64, v bool) (granted int) {
 
 func (r *raft) Step(m pb.Message) error {
 	if m.Type == pb.MsgHup {
-		log.Printf("raft: %x is starting a new election at term %d", r.id, r.Term)
+		raftLogger.Infof("raft: %x is starting a new election at term %d", r.id, r.Term)
 		r.campaign()
 		r.Commit = r.raftLog.committed
 		return nil
@@ -501,12 +500,12 @@ func (r *raft) Step(m pb.Message) error {
 		if m.Type == pb.MsgVote {
 			lead = None
 		}
-		log.Printf("raft: %x [term: %d] received a %s message with higher term from %x [term: %d]",
+		raftLogger.Infof("raft: %x [term: %d] received a %s message with higher term from %x [term: %d]",
 			r.id, r.Term, m.Type, m.From, m.Term)
 		r.becomeFollower(m.Term, lead)
 	case m.Term < r.Term:
 		// ignore
-		log.Printf("raft: %x [term: %d] ignored a %s message with lower term from %x [term: %d]",
+		raftLogger.Infof("raft: %x [term: %d] ignored a %s message with lower term from %x [term: %d]",
 			r.id, r.Term, m.Type, m.From, m.Term)
 		return nil
 	}
@@ -525,7 +524,7 @@ func stepLeader(r *raft, m pb.Message) {
 		r.bcastHeartbeat()
 	case pb.MsgProp:
 		if len(m.Entries) == 0 {
-			log.Panicf("raft: %x stepped empty MsgProp", r.id)
+			raftLogger.Panicf("raft: %x stepped empty MsgProp", r.id)
 		}
 		for i, e := range m.Entries {
 			if e.Type == pb.EntryConfChange {
@@ -540,20 +539,20 @@ func stepLeader(r *raft, m pb.Message) {
 	case pb.MsgAppResp:
 		if pr.isUnreachable() {
 			pr.reachable()
-			log.Printf("raft: %x received msgAppResp from %x and changed it to be reachable [%s]", r.id, m.From, pr)
+			raftLogger.Infof("raft: %x received msgAppResp from %x and changed it to be reachable [%s]", r.id, m.From, pr)
 		}
 		if m.Reject {
-			log.Printf("raft: %x received msgApp rejection(lastindex: %d) from %x for index %d",
+			raftLogger.Infof("raft: %x received msgApp rejection(lastindex: %d) from %x for index %d",
 				r.id, m.RejectHint, m.From, m.Index)
 			if pr.maybeDecrTo(m.Index, m.RejectHint) {
-				log.Printf("raft: %x decreased progress of %x to [%s]", r.id, m.From, pr)
+				raftLogger.Infof("raft: %x decreased progress of %x to [%s]", r.id, m.From, pr)
 				r.sendAppend(m.From)
 			}
 		} else {
 			oldWait := pr.shouldWait()
 			pr.update(m.Index)
 			if r.prs[m.From].maybeSnapshotAbort() {
-				log.Printf("raft: %x snapshot aborted, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
+				raftLogger.Infof("raft: %x snapshot aborted, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
 			}
 			if r.maybeCommit() {
 				r.bcastAppend()
@@ -566,13 +565,13 @@ func stepLeader(r *raft, m pb.Message) {
 	case pb.MsgHeartbeatResp:
 		if pr.isUnreachable() {
 			pr.reachable()
-			log.Printf("raft: %x received msgHeartbeatResp from %x and changed it to be reachable [%s]", r.id, m.From, pr)
+			raftLogger.Infof("raft: %x received msgHeartbeatResp from %x and changed it to be reachable [%s]", r.id, m.From, pr)
 		}
 		if pr.Match < r.raftLog.lastIndex() {
 			r.sendAppend(m.From)
 		}
 	case pb.MsgVote:
-		log.Printf("raft: %x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %d",
+		raftLogger.Infof("raft: %x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %d",
 			r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.From, m.LogTerm, m.Index, r.Term)
 		r.send(pb.Message{To: m.From, Type: pb.MsgVoteResp, Reject: true})
 	case pb.MsgSnapStatus:
@@ -581,10 +580,10 @@ func stepLeader(r *raft, m pb.Message) {
 		}
 		if m.Reject {
 			pr.snapshotFail()
-			log.Printf("raft: %x snapshot failed, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
+			raftLogger.Infof("raft: %x snapshot failed, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
 		} else {
 			pr.snapshotFinish()
-			log.Printf("raft: %x snapshot succeeded, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
+			raftLogger.Infof("raft: %x snapshot succeeded, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
 			// wait for the msgAppResp from the remote node before sending
 			// out the next msgApp
 			pr.waitSet(r.electionTimeout)
@@ -592,7 +591,7 @@ func stepLeader(r *raft, m pb.Message) {
 	case pb.MsgUnreachable:
 		if !pr.isUnreachable() {
 			pr.unreachable()
-			log.Printf("raft: %x failed to send message to %x and changed it to be unreachable [%s]", r.id, m.From, pr)
+			raftLogger.Infof("raft: %x failed to send message to %x and changed it to be unreachable [%s]", r.id, m.From, pr)
 		}
 	}
 }
@@ -600,7 +599,7 @@ func stepLeader(r *raft, m pb.Message) {
 func stepCandidate(r *raft, m pb.Message) {
 	switch m.Type {
 	case pb.MsgProp:
-		log.Printf("raft: %x no leader at term %d; dropping proposal", r.id, r.Term)
+		raftLogger.Infof("raft: %x no leader at term %d; dropping proposal", r.id, r.Term)
 		return
 	case pb.MsgApp:
 		r.becomeFollower(r.Term, m.From)
@@ -612,12 +611,12 @@ func stepCandidate(r *raft, m pb.Message) {
 		r.becomeFollower(m.Term, m.From)
 		r.handleSnapshot(m)
 	case pb.MsgVote:
-		log.Printf("raft: %x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %x",
+		raftLogger.Infof("raft: %x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %x",
 			r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.From, m.LogTerm, m.Index, r.Term)
 		r.send(pb.Message{To: m.From, Type: pb.MsgVoteResp, Reject: true})
 	case pb.MsgVoteResp:
 		gr := r.poll(m.From, !m.Reject)
-		log.Printf("raft: %x [q:%d] has received %d votes and %d vote rejections", r.id, r.q(), gr, len(r.votes)-gr)
+		raftLogger.Infof("raft: %x [q:%d] has received %d votes and %d vote rejections", r.id, r.q(), gr, len(r.votes)-gr)
 		switch r.q() {
 		case gr:
 			r.becomeLeader()
@@ -632,7 +631,7 @@ func stepFollower(r *raft, m pb.Message) {
 	switch m.Type {
 	case pb.MsgProp:
 		if r.lead == None {
-			log.Printf("raft: %x no leader at term %d; dropping proposal", r.id, r.Term)
+			raftLogger.Infof("raft: %x no leader at term %d; dropping proposal", r.id, r.Term)
 			return
 		}
 		m.To = r.lead
@@ -651,12 +650,12 @@ func stepFollower(r *raft, m pb.Message) {
 	case pb.MsgVote:
 		if (r.Vote == None || r.Vote == m.From) && r.raftLog.isUpToDate(m.Index, m.LogTerm) {
 			r.elapsed = 0
-			log.Printf("raft: %x [logterm: %d, index: %d, vote: %x] voted for %x [logterm: %d, index: %d] at term %d",
+			raftLogger.Infof("raft: %x [logterm: %d, index: %d, vote: %x] voted for %x [logterm: %d, index: %d] at term %d",
 				r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.From, m.LogTerm, m.Index, r.Term)
 			r.Vote = m.From
 			r.send(pb.Message{To: m.From, Type: pb.MsgVoteResp})
 		} else {
-			log.Printf("raft: %x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %d",
+			raftLogger.Infof("raft: %x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %d",
 				r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.From, m.LogTerm, m.Index, r.Term)
 			r.send(pb.Message{To: m.From, Type: pb.MsgVoteResp, Reject: true})
 		}
@@ -667,7 +666,7 @@ func (r *raft) handleAppendEntries(m pb.Message) {
 	if mlastIndex, ok := r.raftLog.maybeAppend(m.Index, m.LogTerm, m.Commit, m.Entries...); ok {
 		r.send(pb.Message{To: m.From, Type: pb.MsgAppResp, Index: mlastIndex})
 	} else {
-		log.Printf("raft: %x [logterm: %d, index: %d] rejected msgApp [logterm: %d, index: %d] from %x",
+		raftLogger.Infof("raft: %x [logterm: %d, index: %d] rejected msgApp [logterm: %d, index: %d] from %x",
 			r.id, r.raftLog.term(m.Index), m.Index, m.LogTerm, m.Index, m.From)
 		r.send(pb.Message{To: m.From, Type: pb.MsgAppResp, Index: m.Index, Reject: true, RejectHint: r.raftLog.lastIndex()})
 	}
@@ -681,11 +680,11 @@ func (r *raft) handleHeartbeat(m pb.Message) {
 func (r *raft) handleSnapshot(m pb.Message) {
 	sindex, sterm := m.Snapshot.Metadata.Index, m.Snapshot.Metadata.Term
 	if r.restore(m.Snapshot) {
-		log.Printf("raft: %x [commit: %d] restored snapshot [index: %d, term: %d]",
+		raftLogger.Infof("raft: %x [commit: %d] restored snapshot [index: %d, term: %d]",
 			r.id, r.Commit, sindex, sterm)
 		r.send(pb.Message{To: m.From, Type: pb.MsgAppResp, Index: r.raftLog.lastIndex()})
 	} else {
-		log.Printf("raft: %x [commit: %d] ignored snapshot [index: %d, term: %d]",
+		raftLogger.Infof("raft: %x [commit: %d] ignored snapshot [index: %d, term: %d]",
 			r.id, r.Commit, sindex, sterm)
 		r.send(pb.Message{To: m.From, Type: pb.MsgAppResp, Index: r.raftLog.committed})
 	}
@@ -698,13 +697,13 @@ func (r *raft) restore(s pb.Snapshot) bool {
 		return false
 	}
 	if r.raftLog.matchTerm(s.Metadata.Index, s.Metadata.Term) {
-		log.Printf("raft: %x [commit: %d, lastindex: %d, lastterm: %d] fast-forwarded commit to snapshot [index: %d, term: %d]",
+		raftLogger.Infof("raft: %x [commit: %d, lastindex: %d, lastterm: %d] fast-forwarded commit to snapshot [index: %d, term: %d]",
 			r.id, r.Commit, r.raftLog.lastIndex(), r.raftLog.lastTerm(), s.Metadata.Index, s.Metadata.Term)
 		r.raftLog.commitTo(s.Metadata.Index)
 		return false
 	}
 
-	log.Printf("raft: %x [commit: %d, lastindex: %d, lastterm: %d] starts to restore snapshot [index: %d, term: %d]",
+	raftLogger.Infof("raft: %x [commit: %d, lastindex: %d, lastterm: %d] starts to restore snapshot [index: %d, term: %d]",
 		r.id, r.Commit, r.raftLog.lastIndex(), r.raftLog.lastTerm(), s.Metadata.Index, s.Metadata.Term)
 
 	r.raftLog.restore(s)
@@ -717,7 +716,7 @@ func (r *raft) restore(s pb.Snapshot) bool {
 			match = 0
 		}
 		r.setProgress(n, match, next)
-		log.Printf("raft: %x restored progress of %x [%s]", r.id, n, r.prs[n])
+		raftLogger.Infof("raft: %x restored progress of %x [%s]", r.id, n, r.prs[n])
 	}
 	return true
 }
@@ -761,7 +760,7 @@ func (r *raft) delProgress(id uint64) {
 
 func (r *raft) loadState(state pb.HardState) {
 	if state.Commit < r.raftLog.committed || state.Commit > r.raftLog.lastIndex() {
-		log.Panicf("raft: %x state.commit %d is out of range [%d, %d]", r.id, state.Commit, r.raftLog.committed, r.raftLog.lastIndex())
+		raftLogger.Panicf("raft: %x state.commit %d is out of range [%d, %d]", r.id, state.Commit, r.raftLog.committed, r.raftLog.lastIndex())
 	}
 	r.raftLog.committed = state.Commit
 	r.Term = state.Term

raft/raft_paper_test.go

@@ -28,12 +28,10 @@ package raft
 
 import (
 	"fmt"
-	"io/ioutil"
-	"log"
-	"os"
+	"testing"
+
 	"reflect"
 	"sort"
-	"testing"
 
 	pb "github.com/coreos/etcd/raft/raftpb"
 )
@@ -294,13 +292,13 @@ func TestCandidateFallback(t *testing.T) {
 }
 
 func TestFollowerElectionTimeoutRandomized(t *testing.T) {
-	log.SetOutput(ioutil.Discard)
-	defer log.SetOutput(os.Stderr)
+	SetLogger(discardLogger)
+	defer SetLogger(defaultLogger)
 	testNonleaderElectionTimeoutRandomized(t, StateFollower)
 }
 func TestCandidateElectionTimeoutRandomized(t *testing.T) {
-	log.SetOutput(ioutil.Discard)
-	defer log.SetOutput(os.Stderr)
+	SetLogger(discardLogger)
+	defer SetLogger(defaultLogger)
 	testNonleaderElectionTimeoutRandomized(t, StateCandidate)
 }
 
@@ -335,13 +333,13 @@ func testNonleaderElectionTimeoutRandomized(t *testing.T, state StateType) {
 }
 
 func TestFollowersElectioinTimeoutNonconflict(t *testing.T) {
-	log.SetOutput(ioutil.Discard)
-	defer log.SetOutput(os.Stderr)
+	SetLogger(discardLogger)
+	defer SetLogger(defaultLogger)
 	testNonleadersElectionTimeoutNonconflict(t, StateFollower)
 }
 func TestCandidatesElectionTimeoutNonconflict(t *testing.T) {
-	log.SetOutput(ioutil.Discard)
-	defer log.SetOutput(os.Stderr)
+	SetLogger(discardLogger)
+	defer SetLogger(defaultLogger)
 	testNonleadersElectionTimeoutNonconflict(t, StateCandidate)
 }
 

raft/rafttest/node.go

@@ -59,7 +59,7 @@ func (n *node) start() {
 				n.Step(context.TODO(), m)
 			case <-n.stopc:
 				n.Stop()
-				log.Printf("raft.%d: stop", n.id)
+				raftLogger.Infof("raft.%d: stop", n.id)
 				n.Node = nil
 				close(n.stopc)
 				return

raft/status.go

@@ -16,7 +16,6 @@ package raft
 
 import (
 	"fmt"
-	"log"
 
 	pb "github.com/coreos/etcd/raft/raftpb"
 )
@@ -70,7 +69,7 @@ func (s Status) MarshalJSON() ([]byte, error) {
 func (s Status) String() string {
 	b, err := s.MarshalJSON()
 	if err != nil {
-		log.Panicf("unexpected error: %v", err)
+		raftLogger.Panicf("unexpected error: %v", err)
 	}
 	return string(b)
 }

raft/storage.go

@@ -16,7 +16,6 @@ package raft
 
 import (
 	"errors"
-	"log"
 	"sync"
 
 	pb "github.com/coreos/etcd/raft/raftpb"
@@ -101,7 +100,7 @@ func (ms *MemoryStorage) Entries(lo, hi uint64) ([]pb.Entry, error) {
 		return nil, ErrCompacted
 	}
 	if hi > ms.lastIndex()+1 {
-		log.Panicf("entries's hi(%d) is out of bound lastindex(%d)", hi, ms.lastIndex())
+		raftLogger.Panicf("entries's hi(%d) is out of bound lastindex(%d)", hi, ms.lastIndex())
 	}
 	// only contains dummy entries.
 	if len(ms.ents) == 1 {
@@ -175,7 +174,7 @@ func (ms *MemoryStorage) CreateSnapshot(i uint64, cs *pb.ConfState, data []byte)
 
 	offset := ms.ents[0].Index
 	if i > ms.lastIndex() {
-		log.Panicf("snapshot %d is out of bound lastindex(%d)", i, ms.lastIndex())
+		raftLogger.Panicf("snapshot %d is out of bound lastindex(%d)", i, ms.lastIndex())
 	}
 
 	ms.snapshot.Metadata.Index = i
@@ -196,7 +195,7 @@ func (ms *MemoryStorage) Compact(compactIndex uint64) error {
 		return ErrCompacted
 	}
 	if compactIndex > ms.lastIndex() {
-		log.Panicf("compact %d is out of bound lastindex(%d)", compactIndex, ms.lastIndex())
+		raftLogger.Panicf("compact %d is out of bound lastindex(%d)", compactIndex, ms.lastIndex())
 	}
 
 	i := compactIndex - offset
@@ -237,7 +236,7 @@ func (ms *MemoryStorage) Append(entries []pb.Entry) error {
 	case uint64(len(ms.ents)) == offset:
 		ms.ents = append(ms.ents, entries...)
 	default:
-		log.Panicf("missing log entry [last: %d, append at: %d]",
+		raftLogger.Panicf("missing log entry [last: %d, append at: %d]",
 			ms.lastIndex(), entries[0].Index)
 	}
 	return nil