From de7692b2b2d76ed049adfdda6a19970c664c4354 Mon Sep 17 00:00:00 2001
From: Xiang Li <xiangli.cs@gmail.com>
Date: Sat, 9 Apr 2016 23:30:00 -0700
Subject: [PATCH] etcdserver: do not send out out of date appResp

---
 etcdserver/server.go | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/etcdserver/server.go b/etcdserver/server.go
index 0f6afcd25..9abdb1441 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -938,11 +938,20 @@ func (s *EtcdServer) publish(timeout time.Duration) {
 
 // TODO: move this function into raft.go
 func (s *EtcdServer) send(ms []raftpb.Message) {
-	for i := range ms {
+	sentAppResp := false
+	for i := len(ms) - 1; i >= 0; i-- {
 		if s.cluster.IsIDRemoved(types.ID(ms[i].To)) {
 			ms[i].To = 0
 		}
 
+		if ms[i].Type == raftpb.MsgAppResp {
+			if sentAppResp {
+				ms[i].To = 0
+			} else {
+				sentAppResp = true
+			}
+		}
+
 		if ms[i].Type == raftpb.MsgSnap {
 			// There are two separate data store: the store for v2, and the KV for v3.
 			// The msgSnap only contains the most recent snapshot of store without KV.