From 8558a92fa4100da0a8e6454de7cae6a49e6bcbbb Mon Sep 17 00:00:00 2001
From: Vladimir Mihailenco <vladimir.webdev@gmail.com>
Date: Thu, 13 Oct 2016 13:56:24 +0300
Subject: [PATCH] Retry multiple commands more conservatively.

---
 cluster.go  | 13 +++++++++----
 pipeline.go | 19 ++++++++-----------
 redis.go    | 25 ++++++++++++++-----------
 ring.go     | 39 ++++++++++++++++++++++-----------------
 4 files changed, 53 insertions(+), 43 deletions(-)

diff --git a/cluster.go b/cluster.go
index ff935fc4..9d07d04f 100644
--- a/cluster.go
+++ b/cluster.go
@@ -649,28 +649,33 @@ func (c *ClusterClient) execClusterCmds(
 		if err == nil {
 			continue
 		}
-		if internal.IsNetworkError(err) {
+
+		if i == 0 && internal.IsNetworkError(err) {
 			cmd.reset()
-			failedCmds[nil] = append(failedCmds[nil], cmds[i:]...)
+			failedCmds[nil] = append(failedCmds[nil], cmds...)
 			break
 		}
+
 		moved, ask, addr := internal.IsMovedError(err)
 		if moved {
 			c.lazyReloadSlots()
-			cmd.reset()
+
 			node, err := c.nodeByAddr(addr)
 			if err != nil {
 				setRetErr(err)
 				continue
 			}
+
+			cmd.reset()
 			failedCmds[node] = append(failedCmds[node], cmd)
 		} else if ask {
-			cmd.reset()
 			node, err := c.nodeByAddr(addr)
 			if err != nil {
 				setRetErr(err)
 				continue
 			}
+
+			cmd.reset()
 			failedCmds[node] = append(failedCmds[node], NewCmd("ASKING"), cmd)
 		} else {
 			setRetErr(err)
diff --git a/pipeline.go b/pipeline.go
index 1cbc00f3..ac8bcc2f 100644
--- a/pipeline.go
+++ b/pipeline.go
@@ -84,26 +84,23 @@ func (c *Pipeline) pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
 	return cmds, err
 }
 
-func execCmds(cn *pool.Conn, cmds []Cmder) ([]Cmder, error) {
+func execCmds(cn *pool.Conn, cmds []Cmder) (retry bool, firstErr error) {
 	if err := writeCmd(cn, cmds...); err != nil {
 		setCmdsErr(cmds, err)
-		return cmds, err
+		return true, err
 	}
 
-	var firstCmdErr error
-	var failedCmds []Cmder
-	for _, cmd := range cmds {
+	for i, cmd := range cmds {
 		err := cmd.readReply(cn)
 		if err == nil {
 			continue
 		}
-		if firstCmdErr == nil {
-			firstCmdErr = err
+		if i == 0 && internal.IsNetworkError(err) {
+			return true, err
 		}
-		if internal.IsRetryableError(err) {
-			failedCmds = append(failedCmds, cmd)
+		if firstErr == nil {
+			firstErr = err
 		}
 	}
-
-	return failedCmds, firstCmdErr
+	return false, firstErr
 }
diff --git a/redis.go b/redis.go
index e866a5ca..aee38933 100644
--- a/redis.go
+++ b/redis.go
@@ -197,28 +197,31 @@ func (c *Client) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
 }
 
 func (c *Client) pipelineExec(cmds []Cmder) error {
-	var retErr error
-	failedCmds := cmds
+	var firstErr error
 	for i := 0; i <= c.opt.MaxRetries; i++ {
+		if i > 0 {
+			resetCmds(cmds)
+		}
+
 		cn, _, err := c.conn()
 		if err != nil {
-			setCmdsErr(failedCmds, err)
+			setCmdsErr(cmds, err)
 			return err
 		}
 
-		if i > 0 {
-			resetCmds(failedCmds)
-		}
-		failedCmds, err = execCmds(cn, failedCmds)
+		retry, err := execCmds(cn, cmds)
 		c.putConn(cn, err, false)
-		if err != nil && retErr == nil {
-			retErr = err
+		if err == nil {
+			return nil
 		}
-		if len(failedCmds) == 0 {
+		if firstErr == nil {
+			firstErr = err
+		}
+		if !retry {
 			break
 		}
 	}
-	return retErr
+	return firstErr
 }
 
 func (c *Client) pubSub() *PubSub {
diff --git a/ring.go b/ring.go
index 77193f32..96085346 100644
--- a/ring.go
+++ b/ring.go
@@ -365,9 +365,7 @@ func (c *Ring) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
 	return c.Pipeline().pipelined(fn)
 }
 
-func (c *Ring) pipelineExec(cmds []Cmder) error {
-	var retErr error
-
+func (c *Ring) pipelineExec(cmds []Cmder) (firstErr error) {
 	cmdsMap := make(map[string][]Cmder)
 	for _, cmd := range cmds {
 		cmdInfo := c.cmdInfo(cmd.arg(0))
@@ -379,14 +377,18 @@ func (c *Ring) pipelineExec(cmds []Cmder) error {
 	}
 
 	for i := 0; i <= c.opt.MaxRetries; i++ {
-		failedCmdsMap := make(map[string][]Cmder)
+		var failedCmdsMap map[string][]Cmder
 
 		for name, cmds := range cmdsMap {
+			if i > 0 {
+				resetCmds(cmds)
+			}
+
 			client, err := c.shardByName(name)
 			if err != nil {
 				setCmdsErr(cmds, err)
-				if retErr == nil {
-					retErr = err
+				if firstErr == nil {
+					firstErr = err
 				}
 				continue
 			}
@@ -394,22 +396,25 @@ func (c *Ring) pipelineExec(cmds []Cmder) error {
 			cn, _, err := client.conn()
 			if err != nil {
 				setCmdsErr(cmds, err)
-				if retErr == nil {
-					retErr = err
+				if firstErr == nil {
+					firstErr = err
 				}
 				continue
 			}
 
-			if i > 0 {
-				resetCmds(cmds)
-			}
-			failedCmds, err := execCmds(cn, cmds)
+			retry, err := execCmds(cn, cmds)
 			client.putConn(cn, err, false)
-			if err != nil && retErr == nil {
-				retErr = err
+			if err == nil {
+				continue
 			}
-			if len(failedCmds) > 0 {
-				failedCmdsMap[name] = failedCmds
+			if firstErr == nil {
+				firstErr = err
+			}
+			if retry {
+				if failedCmdsMap == nil {
+					failedCmdsMap = make(map[string][]Cmder)
+				}
+				failedCmdsMap[name] = cmds
 			}
 		}
 
@@ -419,5 +424,5 @@ func (c *Ring) pipelineExec(cmds []Cmder) error {
 		cmdsMap = failedCmdsMap
 	}
 
-	return retErr
+	return firstErr
 }