Replace PoolStats.Requests with PoolStats.Misses

ring.go

@@ -145,9 +145,10 @@ type Ring struct {
 	opt       *RingOptions
 	nreplicas int
 
-	mu     sync.RWMutex
-	hash   *consistenthash.Map
-	shards map[string]*ringShard
+	mu         sync.RWMutex
+	hash       *consistenthash.Map
+	shards     map[string]*ringShard
+	shardsList []*ringShard
 
 	cmdsInfoOnce internal.Once
 	cmdsInfo     map[string]*CommandInfo
@@ -169,12 +170,21 @@ func NewRing(opt *RingOptions) *Ring {
 	for name, addr := range opt.Addrs {
 		clopt := opt.clientOptions()
 		clopt.Addr = addr
-		ring.addClient(name, NewClient(clopt))
+		ring.addShard(name, NewClient(clopt))
 	}
 	go ring.heartbeat()
 	return ring
 }
 
+func (c *Ring) addShard(name string, cl *Client) {
+	shard := &ringShard{Client: cl}
+	c.mu.Lock()
+	c.hash.Add(name)
+	c.shards[name] = shard
+	c.shardsList = append(c.shardsList, shard)
+	c.mu.Unlock()
+}
+
 // Options returns read-only Options that were used to create the client.
 func (c *Ring) Options() *RingOptions {
 	return c.opt
@@ -186,11 +196,15 @@ func (c *Ring) retryBackoff(attempt int) time.Duration {
 
 // PoolStats returns accumulated connection pool stats.
 func (c *Ring) PoolStats() *PoolStats {
+	c.mu.RLock()
+	shards := c.shardsList
+	c.mu.RUnlock()
+
 	var acc PoolStats
-	for _, shard := range c.shards {
+	for _, shard := range shards {
 		s := shard.Client.connPool.Stats()
-		acc.Requests += s.Requests
 		acc.Hits += s.Hits
+		acc.Misses += s.Misses
 		acc.Timeouts += s.Timeouts
 		acc.TotalConns += s.TotalConns
 		acc.FreeConns += s.FreeConns
@@ -229,9 +243,13 @@ func (c *Ring) PSubscribe(channels ...string) *PubSub {
 // ForEachShard concurrently calls the fn on each live shard in the ring.
 // It returns the first error if any.
 func (c *Ring) ForEachShard(fn func(client *Client) error) error {
+	c.mu.RLock()
+	shards := c.shardsList
+	c.mu.RUnlock()
+
 	var wg sync.WaitGroup
 	errCh := make(chan error, 1)
-	for _, shard := range c.shards {
+	for _, shard := range shards {
 		if shard.IsDown() {
 			continue
 		}
@@ -261,10 +279,11 @@ func (c *Ring) ForEachShard(fn func(client *Client) error) error {
 func (c *Ring) cmdInfo(name string) *CommandInfo {
 	err := c.cmdsInfoOnce.Do(func() error {
 		c.mu.RLock()
-		defer c.mu.RUnlock()
+		shards := c.shardsList
+		c.mu.RUnlock()
 
 		var firstErr error
-		for _, shard := range c.shards {
+		for _, shard := range shards {
 			cmdsInfo, err := shard.Client.Command().Result()
 			if err == nil {
 				c.cmdsInfo = cmdsInfo
@@ -286,13 +305,6 @@ func (c *Ring) cmdInfo(name string) *CommandInfo {
 	return info
 }
 
-func (c *Ring) addClient(name string, cl *Client) {
-	c.mu.Lock()
-	c.hash.Add(name)
-	c.shards[name] = &ringShard{Client: cl}
-	c.mu.Unlock()
-}
-
 func (c *Ring) shardByKey(key string) (*ringShard, error) {
 	key = hashtag.Key(key)
 
@@ -372,7 +384,10 @@ func (c *Ring) heartbeat() {
 			break
 		}
 
-		for _, shard := range c.shards {
+		shards := c.shardsList
+		c.mu.RUnlock()
+
+		for _, shard := range shards {
 			err := shard.Client.Ping().Err()
 			if shard.Vote(err == nil || err == pool.ErrPoolTimeout) {
 				internal.Logf("ring shard state changed: %s", shard)
@@ -380,8 +395,6 @@ func (c *Ring) heartbeat() {
 			}
 		}
 
-		c.mu.RUnlock()
-
 		if rebalance {
 			c.rebalance()
 		}
@@ -409,6 +422,7 @@ func (c *Ring) Close() error {
 	}
 	c.hash = nil
 	c.shards = nil
+	c.shardsList = nil
 
 	return firstErr
 }