From e975017b473bd9b2a3d5b23428a8549fe20b1153 Mon Sep 17 00:00:00 2001
From: mmukhi <mmukhi@google.com>
Date: Thu, 4 Jan 2018 11:16:47 -0800
Subject: [PATCH] Don't set reconnect parameters when the server has already
 responded. (#1779)

---
 clientconn.go | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/clientconn.go b/clientconn.go
index 1d079eb2..bfbef362 100644
--- a/clientconn.go
+++ b/clientconn.go
@@ -1119,8 +1119,8 @@ func (ac *addrConn) createTransport(connectRetryNum, ridx int, backoffDeadline,
 		}
 		done := make(chan struct{})
 		onPrefaceReceipt := func() {
-			close(done)
 			ac.mu.Lock()
+			close(done)
 			if !ac.backoffDeadline.IsZero() {
 				// If we haven't already started reconnecting to
 				// other backends.
@@ -1185,10 +1185,16 @@ func (ac *addrConn) createTransport(connectRetryNum, ridx int, backoffDeadline,
 			close(ac.ready)
 			ac.ready = nil
 		}
-		ac.connectRetryNum = connectRetryNum
-		ac.backoffDeadline = backoffDeadline
-		ac.connectDeadline = connectDeadline
-		ac.reconnectIdx = i + 1 // Start reconnecting from the next backend in the list.
+		select {
+		case <-done:
+			// If the server has responded back with preface already,
+			// don't set the reconnect parameters.
+		default:
+			ac.connectRetryNum = connectRetryNum
+			ac.backoffDeadline = backoffDeadline
+			ac.connectDeadline = connectDeadline
+			ac.reconnectIdx = i + 1 // Start reconnecting from the next backend in the list.
+		}
 		ac.mu.Unlock()
 		return true, nil
 	}