Merge pull request #1711 from bdarnell/stable-restart

raft: Only call stableTo when we have ready entries or a snapshot.

raft/node.go

@@ -226,6 +226,7 @@ func (n *node) run(r *raft) {
 	var readyc chan Ready
 	var advancec chan struct{}
 	var prevLastUnstablei uint64
+	var havePrevLastUnstablei bool
 	var rd Ready
 
 	lead := None
@@ -294,6 +295,7 @@ func (n *node) run(r *raft) {
 			}
 			if len(rd.Entries) > 0 {
 				prevLastUnstablei = rd.Entries[len(rd.Entries)-1].Index
+				havePrevLastUnstablei = true
 			}
 			if !IsEmptyHardState(rd.HardState) {
 				prevHardSt = rd.HardState
@@ -302,6 +304,7 @@ func (n *node) run(r *raft) {
 				prevSnapi = rd.Snapshot.Index
 				if prevSnapi > prevLastUnstablei {
 					prevLastUnstablei = prevSnapi
+					havePrevLastUnstablei = true
 				}
 			}
 			r.msgs = nil
@@ -310,7 +313,10 @@ func (n *node) run(r *raft) {
 			if prevHardSt.Commit != 0 {
 				r.raftLog.appliedTo(prevHardSt.Commit)
 			}
-			r.raftLog.stableTo(prevLastUnstablei)
+			if havePrevLastUnstablei {
+				r.raftLog.stableTo(prevLastUnstablei)
+				havePrevLastUnstablei = false
+			}
 			advancec = nil
 		case <-n.stop:
 			close(n.done)

raft/node_test.go

@@ -336,7 +336,7 @@ func TestNodeStart(t *testing.T) {
 	select {
 	case rd := <-n.Ready():
 		t.Errorf("unexpected Ready: %+v", rd)
-	default:
+	case <-time.After(time.Millisecond):
 	}
 }
 
@@ -364,7 +364,7 @@ func TestNodeRestart(t *testing.T) {
 	select {
 	case rd := <-n.Ready():
 		t.Errorf("unexpected Ready: %+v", rd)
-	default:
+	case <-time.After(time.Millisecond):
 	}
 }
 
@@ -432,12 +432,12 @@ func TestNodeAdvance(t *testing.T) {
 	select {
 	case rd := <-n.Ready():
 		t.Fatalf("unexpected Ready before Advance: %+v", rd)
-	default:
+	case <-time.After(time.Millisecond):
 	}
 	n.Advance()
 	select {
 	case <-n.Ready():
-	default:
+	case <-time.After(time.Millisecond):
 		t.Errorf("expect Ready after Advance, but there is no Ready available")
 	}
 }