raft: pass Progress to maybeSendAppend

Signed-off-by: Pavel Kalinnikov <pavel@cockroachlabs.com>

Author: pav-kv

raft.go

@@ -596,9 +596,7 @@ func (r *raft) send(m pb.Message) {
 // argument controls whether messages with no entries will be sent
 // ("empty" messages are useful to convey updated Commit indexes, but
 // are undesirable when we're sending multiple messages in a batch).
-func (r *raft) maybeSendAppend(to uint64) bool {
-	pr := r.trk.Progress[to]
-
+func (r *raft) maybeSendAppend(to uint64, pr *tracker.Progress) bool {
 	last, commit := r.raftLog.lastIndex(), r.raftLog.committed
 	if !pr.ShouldSendMsgApp(last, commit) {
 		return false
@@ -685,11 +683,11 @@ func (r *raft) sendHeartbeat(to uint64, ctx []byte) {
 // bcastAppend sends RPC, with entries to all peers that are not up-to-date
 // according to the progress recorded in r.trk.
 func (r *raft) bcastAppend() {
-	r.trk.Visit(func(id uint64, _ *tracker.Progress) {
+	r.trk.Visit(func(id uint64, pr *tracker.Progress) {
 		if id == r.id {
 			return
 		}
-		r.maybeSendAppend(id)
+		r.maybeSendAppend(id, pr)
 	})
 }
 
@@ -1467,7 +1465,7 @@ func stepLeader(r *raft, m pb.Message) error {
 				if pr.State == tracker.StateReplicate {
 					pr.BecomeProbe()
 				}
-				r.maybeSendAppend(m.From)
+				r.maybeSendAppend(m.From, pr)
 			}
 		} else {
 			// We want to update our tracking if the response updates our
@@ -1512,7 +1510,7 @@ func stepLeader(r *raft, m pb.Message) error {
 				// transitioning from probe to replicate, or when freeTo() covers
 				// multiple messages). Send as many messages as we can.
 				if r.id != m.From {
-					for r.maybeSendAppend(m.From) {
+					for r.maybeSendAppend(m.From, pr) {
 					}
 				}
 				// Transfer leadership is in progress.
@@ -1525,7 +1523,7 @@ func stepLeader(r *raft, m pb.Message) error {
 	case pb.MsgHeartbeatResp:
 		pr.RecentActive = true
 		pr.MsgAppFlowPaused = false
-		r.maybeSendAppend(m.From)
+		r.maybeSendAppend(m.From, pr)
 
 		if r.readOnly.option != ReadOnlySafe || len(m.Context) == 0 {
 			return nil
@@ -1596,7 +1594,7 @@ func stepLeader(r *raft, m pb.Message) error {
 			r.logger.Infof("%x sends MsgTimeoutNow to %x immediately as %x already has up-to-date log", r.id, leadTransferee, leadTransferee)
 		} else {
 			pr.MsgAppFlowPaused = false
-			r.maybeSendAppend(leadTransferee)
+			r.maybeSendAppend(leadTransferee, pr)
 		}
 	}
 	return nil

raft_test.go

@@ -2764,7 +2764,8 @@ func TestSendAppendForProgressProbe(t *testing.T) {
 	r.becomeCandidate()
 	r.becomeLeader()
 	r.readMessages()
-	r.trk.Progress[2].BecomeProbe()
+	pr2 := r.trk.Progress[2]
+	pr2.BecomeProbe()
 
 	// each round is a heartbeat
 	for i := 0; i < 3; i++ {
@@ -2773,7 +2774,7 @@ func TestSendAppendForProgressProbe(t *testing.T) {
 			// loop. After that, the follower is paused until a heartbeat response is
 			// received.
 			mustAppendEntry(r, pb.Entry{Data: []byte("somedata")})
-			r.maybeSendAppend(2)
+			r.maybeSendAppend(2, pr2)
 			msg := r.readMessages()
 			if len(msg) != 1 {
 				t.Errorf("len(msg) = %d, want %d", len(msg), 1)
@@ -2788,7 +2789,7 @@ func TestSendAppendForProgressProbe(t *testing.T) {
 		}
 		for j := 0; j < 10; j++ {
 			mustAppendEntry(r, pb.Entry{Data: []byte("somedata")})
-			r.maybeSendAppend(2)
+			r.maybeSendAppend(2, pr2)
 			if l := len(r.readMessages()); l != 0 {
 				t.Errorf("len(msg) = %d, want %d", l, 0)
 			}
@@ -2831,11 +2832,12 @@ func TestSendAppendForProgressReplicate(t *testing.T) {
 	r.becomeCandidate()
 	r.becomeLeader()
 	r.readMessages()
-	r.trk.Progress[2].BecomeReplicate()
+	pr2 := r.trk.Progress[2]
+	pr2.BecomeReplicate()
 
 	for i := 0; i < 10; i++ {
 		mustAppendEntry(r, pb.Entry{Data: []byte("somedata")})
-		r.maybeSendAppend(2)
+		r.maybeSendAppend(2, pr2)
 		msgs := r.readMessages()
 		if len(msgs) != 1 {
 			t.Errorf("len(msg) = %d, want %d", len(msgs), 1)
@@ -2848,11 +2850,12 @@ func TestSendAppendForProgressSnapshot(t *testing.T) {
 	r.becomeCandidate()
 	r.becomeLeader()
 	r.readMessages()
-	r.trk.Progress[2].BecomeSnapshot(10)
+	pr2 := r.trk.Progress[2]
+	pr2.BecomeSnapshot(10)
 
 	for i := 0; i < 10; i++ {
 		mustAppendEntry(r, pb.Entry{Data: []byte("somedata")})
-		r.maybeSendAppend(2)
+		r.maybeSendAppend(2, pr2)
 		msgs := r.readMessages()
 		if len(msgs) != 0 {
 			t.Errorf("len(msg) = %d, want %d", len(msgs), 0)
@@ -4671,16 +4674,17 @@ func TestLogReplicationWithReorderedMessage(t *testing.T) {
 	r1.becomeCandidate()
 	r1.becomeLeader()
 	r1.readMessages()
-	r1.trk.Progress[2].BecomeReplicate()
+	pr2 := r1.trk.Progress[2]
+	pr2.BecomeReplicate()
 
 	r2 := newTestRaft(2, 10, 1, newTestMemoryStorage(withPeers(1, 2)))
 
 	// r1 sends 2 MsgApp messages to r2.
 	mustAppendEntry(r1, pb.Entry{Data: []byte("somedata")})
-	r1.maybeSendAppend(2)
+	r1.maybeSendAppend(2, pr2)
 	req1 := expectOneMessage(t, r1)
 	mustAppendEntry(r1, pb.Entry{Data: []byte("somedata")})
-	r1.maybeSendAppend(2)
+	r1.maybeSendAppend(2, pr2)
 	req2 := expectOneMessage(t, r1)
 
 	// r2 receives the second MsgApp first due to reordering.