Merge pull request #2004 from xiang90/status

raft: add Status interface

etcdserver/server_test.go

@@ -1300,15 +1300,18 @@ func (n *nodeRecorder) Step(ctx context.Context, msg raftpb.Message) error {
 	n.Record(testutil.Action{Name: "Step"})
 	return nil
 }
+func (n *nodeRecorder) Status() raft.Status      { return raft.Status{} }
 func (n *nodeRecorder) Ready() <-chan raft.Ready { return nil }
 func (n *nodeRecorder) Advance()                 {}
 func (n *nodeRecorder) ApplyConfChange(conf raftpb.ConfChange) *raftpb.ConfState {
 	n.Record(testutil.Action{Name: "ApplyConfChange", Params: []interface{}{conf}})
 	return &raftpb.ConfState{}
 }
+
 func (n *nodeRecorder) Stop() {
 	n.Record(testutil.Action{Name: "Stop"})
 }
+
 func (n *nodeRecorder) Compact(index uint64, nodes []uint64, d []byte) {
 	n.Record(testutil.Action{Name: "Compact"})
 }

raft/node.go

@@ -119,6 +119,8 @@ type Node interface {
 	// in snapshots. Will never return nil; it returns a pointer only
 	// to match MemoryStorage.Compact.
 	ApplyConfChange(cc pb.ConfChange) *pb.ConfState
+	// Status returns the current status of the raft state machine.
+	Status() Status
 	// Stop performs any necessary termination of the Node
 	Stop()
 }
@@ -190,6 +192,7 @@ type node struct {
 	tickc      chan struct{}
 	done       chan struct{}
 	stop       chan struct{}
+	status     chan chan Status
 }
 
 func newNode() node {
@@ -203,6 +206,7 @@ func newNode() node {
 		tickc:      make(chan struct{}),
 		done:       make(chan struct{}),
 		stop:       make(chan struct{}),
+		status:     make(chan chan Status),
 	}
 }
 
@@ -222,8 +226,7 @@ func (n *node) run(r *raft) {
 	var propc chan pb.Message
 	var readyc chan Ready
 	var advancec chan struct{}
-	var prevLastUnstablei uint64
-	var prevLastUnstablet uint64
+	var prevLastUnstablei, prevLastUnstablet uint64
 	var havePrevLastUnstablei bool
 	var prevSnapi uint64
 	var rd Ready
@@ -328,6 +331,8 @@ func (n *node) run(r *raft) {
 			}
 			r.raftLog.stableSnapTo(prevSnapi)
 			advancec = nil
+		case c := <-n.status:
+			c <- getStatus(r)
 		case <-n.stop:
 			close(n.done)
 			return
@@ -407,6 +412,12 @@ func (n *node) ApplyConfChange(cc pb.ConfChange) *pb.ConfState {
 	return &cs
 }
 
+func (n *node) Status() Status {
+	c := make(chan Status)
+	n.status <- c
+	return <-c
+}
+
 func newReady(r *raft, prevSoftSt *SoftState, prevHardSt pb.HardState) Ready {
 	rd := Ready{
 		Entries:          r.raftLog.unstableEntries(),

raft/raft.go

@@ -52,61 +52,61 @@ func (st StateType) String() string {
 	return stmap[uint64(st)]
 }
 
-type progress struct {
-	match, next uint64
-	wait        int
+type Progress struct {
+	Match, Next uint64
+	Wait        int
 }
 
-func (pr *progress) update(n uint64) {
+func (pr *Progress) update(n uint64) {
 	pr.waitReset()
-	if pr.match < n {
-		pr.match = n
+	if pr.Match < n {
+		pr.Match = n
 	}
-	if pr.next < n+1 {
-		pr.next = n + 1
+	if pr.Next < n+1 {
+		pr.Next = n + 1
 	}
 }
 
-func (pr *progress) optimisticUpdate(n uint64) { pr.next = n + 1 }
+func (pr *Progress) optimisticUpdate(n uint64) { pr.Next = n + 1 }
 
 // maybeDecrTo returns false if the given to index comes from an out of order message.
 // Otherwise it decreases the progress next index to min(rejected, last) and returns true.
-func (pr *progress) maybeDecrTo(rejected, last uint64) bool {
+func (pr *Progress) maybeDecrTo(rejected, last uint64) bool {
 	pr.waitReset()
-	if pr.match != 0 {
+	if pr.Match != 0 {
 		// the rejection must be stale if the progress has matched and "rejected"
 		// is smaller than "match".
-		if rejected <= pr.match {
+		if rejected <= pr.Match {
 			return false
 		}
 		// directly decrease next to match + 1
-		pr.next = pr.match + 1
+		pr.Next = pr.Match + 1
 		return true
 	}
 
 	// the rejection must be stale if "rejected" does not match next - 1
-	if pr.next-1 != rejected {
+	if pr.Next-1 != rejected {
 		return false
 	}
 
-	if pr.next = min(rejected, last+1); pr.next < 1 {
-		pr.next = 1
+	if pr.Next = min(rejected, last+1); pr.Next < 1 {
+		pr.Next = 1
 	}
 	return true
 }
 
-func (pr *progress) waitDecr(i int) {
-	pr.wait -= i
-	if pr.wait < 0 {
-		pr.wait = 0
+func (pr *Progress) waitDecr(i int) {
+	pr.Wait -= i
+	if pr.Wait < 0 {
+		pr.Wait = 0
 	}
 }
-func (pr *progress) waitSet(w int)    { pr.wait = w }
-func (pr *progress) waitReset()       { pr.wait = 0 }
-func (pr *progress) shouldWait() bool { return pr.match == 0 && pr.wait > 0 }
+func (pr *Progress) waitSet(w int)    { pr.Wait = w }
+func (pr *Progress) waitReset()       { pr.Wait = 0 }
+func (pr *Progress) shouldWait() bool { return pr.Match == 0 && pr.Wait > 0 }
 
-func (pr *progress) String() string {
-	return fmt.Sprintf("next = %d, match = %d, wait = %v", pr.next, pr.match, pr.wait)
+func (pr *Progress) String() string {
+	return fmt.Sprintf("next = %d, match = %d, wait = %v", pr.Next, pr.Match, pr.Wait)
 }
 
 type raft struct {
@@ -117,7 +117,7 @@ type raft struct {
 	// the log
 	raftLog *raftLog
 
-	prs map[uint64]*progress
+	prs map[uint64]*Progress
 
 	state StateType
 
@@ -161,13 +161,13 @@ func newRaft(id uint64, peers []uint64, election, heartbeat int, storage Storage
 		id:               id,
 		lead:             None,
 		raftLog:          raftlog,
-		prs:              make(map[uint64]*progress),
+		prs:              make(map[uint64]*Progress),
 		electionTimeout:  election,
 		heartbeatTimeout: heartbeat,
 	}
 	r.rand = rand.New(rand.NewSource(int64(id)))
 	for _, p := range peers {
-		r.prs[p] = &progress{next: 1}
+		r.prs[p] = &Progress{Next: 1}
 	}
 	if !isHardStateEqual(hs, emptyState) {
 		r.loadState(hs)
@@ -220,7 +220,7 @@ func (r *raft) sendAppend(to uint64) {
 	}
 	m := pb.Message{}
 	m.To = to
-	if r.needSnapshot(pr.next) {
+	if r.needSnapshot(pr.Next) {
 		m.Type = pb.MsgSnap
 		snapshot, err := r.raftLog.snapshot()
 		if err != nil {
@@ -236,15 +236,15 @@ func (r *raft) sendAppend(to uint64) {
 		pr.waitSet(r.electionTimeout)
 	} else {
 		m.Type = pb.MsgApp
-		m.Index = pr.next - 1
-		m.LogTerm = r.raftLog.term(pr.next - 1)
-		m.Entries = r.raftLog.entries(pr.next)
+		m.Index = pr.Next - 1
+		m.LogTerm = r.raftLog.term(pr.Next - 1)
+		m.Entries = r.raftLog.entries(pr.Next)
 		m.Commit = r.raftLog.committed
 		// optimistically increase the next if the follower
 		// has been matched.
-		if n := len(m.Entries); pr.match != 0 && n != 0 {
+		if n := len(m.Entries); pr.Match != 0 && n != 0 {
 			pr.optimisticUpdate(m.Entries[n-1].Index)
-		} else if pr.match == 0 {
+		} else if pr.Match == 0 {
 			// TODO (xiangli): better way to find out if the follower is in good path or not
 			// a follower might be in bad path even if match != 0, since we optimistically
 			// increase the next.
@@ -262,7 +262,7 @@ func (r *raft) sendHeartbeat(to uint64) {
 	// or it might not have all the committed entries.
 	// The leader MUST NOT forward the follower's commit to
 	// an unmatched index.
-	commit := min(r.prs[to].match, r.raftLog.committed)
+	commit := min(r.prs[to].Match, r.raftLog.committed)
 	m := pb.Message{
 		To:     to,
 		Type:   pb.MsgHeartbeat,
@@ -297,7 +297,7 @@ func (r *raft) maybeCommit() bool {
 	// TODO(bmizerany): optimize.. Currently naive
 	mis := make(uint64Slice, 0, len(r.prs))
 	for i := range r.prs {
-		mis = append(mis, r.prs[i].match)
+		mis = append(mis, r.prs[i].Match)
 	}
 	sort.Sort(sort.Reverse(mis))
 	mci := mis[r.q()-1]
@@ -311,9 +311,9 @@ func (r *raft) reset(term uint64) {
 	r.elapsed = 0
 	r.votes = make(map[uint64]bool)
 	for i := range r.prs {
-		r.prs[i] = &progress{next: r.raftLog.lastIndex() + 1}
+		r.prs[i] = &Progress{Next: r.raftLog.lastIndex() + 1}
 		if i == r.id {
-			r.prs[i].match = r.raftLog.lastIndex()
+			r.prs[i].Match = r.raftLog.lastIndex()
 		}
 	}
 	r.pendingConf = false
@@ -495,7 +495,7 @@ func stepLeader(r *raft, m pb.Message) {
 			}
 		}
 	case pb.MsgHeartbeatResp:
-		if r.prs[m.From].match < r.raftLog.lastIndex() {
+		if r.prs[m.From].Match < r.raftLog.lastIndex() {
 			r.sendAppend(m.From)
 		}
 	case pb.MsgVote:
@@ -616,7 +616,7 @@ func (r *raft) restore(s pb.Snapshot) bool {
 		r.id, r.Commit, r.raftLog.lastIndex(), r.raftLog.lastTerm(), s.Metadata.Index, s.Metadata.Term)
 
 	r.raftLog.restore(s)
-	r.prs = make(map[uint64]*progress)
+	r.prs = make(map[uint64]*Progress)
 	for _, n := range s.Metadata.ConfState.Nodes {
 		match, next := uint64(0), uint64(r.raftLog.lastIndex())+1
 		if n == r.id {
@@ -660,7 +660,7 @@ func (r *raft) removeNode(id uint64) {
 func (r *raft) resetPendingConf() { r.pendingConf = false }
 
 func (r *raft) setProgress(id, match, next uint64) {
-	r.prs[id] = &progress{next: next, match: match}
+	r.prs[id] = &Progress{Next: next, Match: match}
 }
 
 func (r *raft) delProgress(id uint64) {

raft/raft_test.go

@@ -64,16 +64,16 @@ func TestProgressUpdate(t *testing.T) {
 		{prevM + 2, prevM + 2, prevN + 1}, // increase match, next
 	}
 	for i, tt := range tests {
-		p := &progress{
-			match: prevM,
-			next:  prevN,
+		p := &Progress{
+			Match: prevM,
+			Next:  prevN,
 		}
 		p.update(tt.update)
-		if p.match != tt.wm {
-			t.Errorf("#%d: match= %d, want %d", i, p.match, tt.wm)
+		if p.Match != tt.wm {
+			t.Errorf("#%d: match= %d, want %d", i, p.Match, tt.wm)
 		}
-		if p.next != tt.wn {
-			t.Errorf("#%d: next= %d, want %d", i, p.next, tt.wn)
+		if p.Next != tt.wn {
+			t.Errorf("#%d: next= %d, want %d", i, p.Next, tt.wn)
 		}
 	}
 }
@@ -136,17 +136,17 @@ func TestProgressMaybeDecr(t *testing.T) {
 		},
 	}
 	for i, tt := range tests {
-		p := &progress{
-			match: tt.m,
-			next:  tt.n,
+		p := &Progress{
+			Match: tt.m,
+			Next:  tt.n,
 		}
 		if g := p.maybeDecrTo(tt.rejected, tt.last); g != tt.w {
 			t.Errorf("#%d: maybeDecrTo= %t, want %t", i, g, tt.w)
 		}
-		if gm := p.match; gm != tt.m {
+		if gm := p.Match; gm != tt.m {
 			t.Errorf("#%d: match= %d, want %d", i, gm, tt.m)
 		}
-		if gn := p.next; gn != tt.wn {
+		if gn := p.Next; gn != tt.wn {
 			t.Errorf("#%d: next= %d, want %d", i, gn, tt.wn)
 		}
 	}
@@ -166,9 +166,9 @@ func TestProgressShouldWait(t *testing.T) {
 		{0, 0, false},
 	}
 	for i, tt := range tests {
-		p := &progress{
-			match: tt.m,
-			wait:  tt.wait,
+		p := &Progress{
+			Match: tt.m,
+			Wait:  tt.wait,
 		}
 		if g := p.shouldWait(); g != tt.w {
 			t.Errorf("#%d: shouldwait = %t, want %t", i, g, tt.w)
@@ -179,17 +179,17 @@ func TestProgressShouldWait(t *testing.T) {
 // TestProgressWaitReset ensures that progress.Update and progress.DercTo
 // will reset progress.wait.
 func TestProgressWaitReset(t *testing.T) {
-	p := &progress{
-		wait: 1,
+	p := &Progress{
+		Wait: 1,
 	}
 	p.maybeDecrTo(1, 1)
-	if p.wait != 0 {
-		t.Errorf("wait= %d, want 0", p.wait)
+	if p.Wait != 0 {
+		t.Errorf("wait= %d, want 0", p.Wait)
 	}
-	p.wait = 1
+	p.Wait = 1
 	p.update(2)
-	if p.wait != 0 {
-		t.Errorf("wait= %d, want 0", p.wait)
+	if p.Wait != 0 {
+		t.Errorf("wait= %d, want 0", p.Wait)
 	}
 }
 
@@ -198,11 +198,11 @@ func TestProgressDecr(t *testing.T) {
 	r := newRaft(1, []uint64{1, 2}, 5, 1, NewMemoryStorage())
 	r.becomeCandidate()
 	r.becomeLeader()
-	r.prs[2].wait = r.heartbeatTimeout * 2
+	r.prs[2].Wait = r.heartbeatTimeout * 2
 
 	r.Step(pb.Message{From: 1, To: 1, Type: pb.MsgBeat})
-	if r.prs[2].wait != r.heartbeatTimeout*(2-1) {
-		t.Errorf("wait = %d, want %d", r.prs[2].wait, r.heartbeatTimeout*(2-1))
+	if r.prs[2].Wait != r.heartbeatTimeout*(2-1) {
+		t.Errorf("wait = %d, want %d", r.prs[2].Wait, r.heartbeatTimeout*(2-1))
 	}
 }
 
@@ -1073,11 +1073,11 @@ func TestLeaderAppResp(t *testing.T) {
 		sm.Step(pb.Message{From: 2, Type: pb.MsgAppResp, Index: tt.index, Term: sm.Term, Reject: tt.reject, RejectHint: tt.index})
 
 		p := sm.prs[2]
-		if p.match != tt.wmatch {
-			t.Errorf("#%d match = %d, want %d", i, p.match, tt.wmatch)
+		if p.Match != tt.wmatch {
+			t.Errorf("#%d match = %d, want %d", i, p.Match, tt.wmatch)
 		}
-		if p.next != tt.wnext {
-			t.Errorf("#%d next = %d, want %d", i, p.next, tt.wnext)
+		if p.Next != tt.wnext {
+			t.Errorf("#%d next = %d, want %d", i, p.Next, tt.wnext)
 		}
 
 		msgs := sm.readMessages()
@@ -1119,9 +1119,9 @@ func TestBcastBeat(t *testing.T) {
 		sm.appendEntry(pb.Entry{Index: uint64(i) + 1})
 	}
 	// slow follower
-	sm.prs[2].match, sm.prs[2].next = 5, 6
+	sm.prs[2].Match, sm.prs[2].Next = 5, 6
 	// normal follower
-	sm.prs[3].match, sm.prs[3].next = sm.raftLog.lastIndex(), sm.raftLog.lastIndex()+1
+	sm.prs[3].Match, sm.prs[3].Next = sm.raftLog.lastIndex(), sm.raftLog.lastIndex()+1
 
 	sm.Step(pb.Message{Type: pb.MsgBeat})
 	msgs := sm.readMessages()
@@ -1129,8 +1129,8 @@ func TestBcastBeat(t *testing.T) {
 		t.Fatalf("len(msgs) = %v, want 2", len(msgs))
 	}
 	wantCommitMap := map[uint64]uint64{
-		2: min(sm.raftLog.committed, sm.prs[2].match),
-		3: min(sm.raftLog.committed, sm.prs[3].match),
+		2: min(sm.raftLog.committed, sm.prs[2].Match),
+		3: min(sm.raftLog.committed, sm.prs[3].Match),
 	}
 	for i, m := range msgs {
 		if m.Type != pb.MsgHeartbeat {
@@ -1216,12 +1216,12 @@ func TestLeaderIncreaseNext(t *testing.T) {
 		sm.raftLog.append(previousEnts...)
 		sm.becomeCandidate()
 		sm.becomeLeader()
-		sm.prs[2].match, sm.prs[2].next = tt.match, tt.next
+		sm.prs[2].Match, sm.prs[2].Next = tt.match, tt.next
 		sm.Step(pb.Message{From: 1, To: 1, Type: pb.MsgProp, Entries: []pb.Entry{{Data: []byte("somedata")}}})
 
 		p := sm.prs[2]
-		if p.next != tt.wnext {
-			t.Errorf("#%d next = %d, want %d", i, p.next, tt.wnext)
+		if p.Next != tt.wnext {
+			t.Errorf("#%d next = %d, want %d", i, p.Next, tt.wnext)
 		}
 	}
 }
@@ -1310,9 +1310,9 @@ func TestProvideSnap(t *testing.T) {
 
 	// force set the next of node 1, so that
 	// node 1 needs a snapshot
-	sm.prs[2].next = sm.raftLog.firstIndex()
+	sm.prs[2].Next = sm.raftLog.firstIndex()
 
-	sm.Step(pb.Message{From: 2, To: 1, Type: pb.MsgAppResp, Index: sm.prs[2].next - 1, Reject: true})
+	sm.Step(pb.Message{From: 2, To: 1, Type: pb.MsgAppResp, Index: sm.prs[2].Next - 1, Reject: true})
 	msgs := sm.readMessages()
 	if len(msgs) != 1 {
 		t.Fatalf("len(msgs) = %d, want 1", len(msgs))
@@ -1547,9 +1547,9 @@ func newNetwork(peers ...Interface) *network {
 			npeers[id] = sm
 		case *raft:
 			v.id = id
-			v.prs = make(map[uint64]*progress)
+			v.prs = make(map[uint64]*Progress)
 			for i := 0; i < size; i++ {
-				v.prs[peerAddrs[i]] = &progress{}
+				v.prs[peerAddrs[i]] = &Progress{}
 			}
 			v.reset(0)
 			npeers[id] = v

raft/status.go

@@ -0,0 +1,49 @@
+/*
+   Copyright 2014 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 (
+	pb "github.com/coreos/etcd/raft/raftpb"
+)
+
+type Status struct {
+	ID uint64
+
+	pb.HardState
+	SoftState
+
+	Applied  uint64
+	Progress map[uint64]Progress
+}
+
+// getStatus gets a copy of the current raft status.
+func getStatus(r *raft) Status {
+	s := Status{ID: r.id}
+	s.HardState = r.HardState
+	s.SoftState = *r.softState()
+
+	s.Applied = r.raftLog.applied
+
+	if s.RaftState == StateLeader {
+		s.Progress = make(map[uint64]Progress)
+		for id, p := range r.prs {
+			s.Progress[id] = *p
+		}
+	}
+
+	return s
+}