diff --git a/broker/broker.go b/broker/broker.go
index a7321c64..0571ade7 100644
--- a/broker/broker.go
+++ b/broker/broker.go
@@ -253,7 +253,7 @@ func (b *Broker) handleConnection(typ int, conn net.Conn, idx uint64) {
 	connack.SessionPresent = msg.CleanSession
 	err = connack.Write(conn)
 	if err != nil {
-		log.Error("send connack error, ", err)
+		log.Error("send connack error, ", err, " clientID = ", msg.ClientIdentifier)
 		return
 	}
 
@@ -295,10 +295,11 @@ func (b *Broker) handleConnection(typ int, conn net.Conn, idx uint64) {
 		c.mp = msgPool
 		old, exist = b.clients.Load(cid)
 		if exist {
-			log.Warn("client exist, close old...")
+			log.Warn("client exist, close old...", " clientID = ", c.info.clientID)
 			ol, ok := old.(*client)
 			if ok {
-				ol.Close()
+				msg := &Message{client: c, packet: DisconnectdPacket}
+				ol.mp.queue <- msg
 			}
 		}
 		b.clients.Store(cid, c)
diff --git a/broker/client.go b/broker/client.go
index c9966bbd..532f6043 100644
--- a/broker/client.go
+++ b/broker/client.go
@@ -102,7 +102,7 @@ func (c *client) readLoop() {
 		}
 		packet, err := packets.ReadPacket(nc)
 		if err != nil {
-			log.Error("read packet error: ", err)
+			log.Error("read packet error: ", err, " clientID = ", c.info.clientID)
 			break
 		}
 		// log.Info("recv buf: ", packet)
@@ -124,45 +124,33 @@ func ProcessMessage(msg *Message) {
 	if ca == nil {
 		return
 	}
+	log.Debug("Recv message: ", ca.String(), " clientID = ", c.info.clientID)
 	switch ca.(type) {
 	case *packets.ConnackPacket:
-		// log.Info("Recv conack message..........")
+
 	case *packets.ConnectPacket:
-		// log.Info("Recv connect message..........")
 	case *packets.PublishPacket:
-		// log.Info("Recv publish message..........")
 		packet := ca.(*packets.PublishPacket)
 		c.ProcessPublish(packet)
 	case *packets.PubackPacket:
-		//log.Info("Recv publish  ack message..........")
 	case *packets.PubrecPacket:
-		//log.Info("Recv publish rec message..........")
 	case *packets.PubrelPacket:
-		//log.Info("Recv publish rel message..........")
 	case *packets.PubcompPacket:
-		//log.Info("Recv publish  ack message..........")
 	case *packets.SubscribePacket:
-		// log.Info("Recv subscribe message.....")
 		packet := ca.(*packets.SubscribePacket)
 		c.ProcessSubscribe(packet)
 	case *packets.SubackPacket:
-		// log.Info("Recv suback message.....")
 	case *packets.UnsubscribePacket:
-		// log.Info("Recv unsubscribe message.....")
 		packet := ca.(*packets.UnsubscribePacket)
 		c.ProcessUnSubscribe(packet)
 	case *packets.UnsubackPacket:
-		//log.Info("Recv unsuback message.....")
 	case *packets.PingreqPacket:
-		// log.Info("Recv PINGREQ message..........")
 		c.ProcessPing()
 	case *packets.PingrespPacket:
-		//log.Info("Recv PINGRESP message..........")
 	case *packets.DisconnectPacket:
-		// log.Info("Recv DISCONNECT message.......")
 		c.Close()
 	default:
-		log.Info("Recv Unknow message.......")
+		log.Info("Recv Unknow message.......", " clientID = ", c.info.clientID)
 	}
 }
 
@@ -173,7 +161,7 @@ func (c *client) ProcessPublish(packet *packets.PublishPacket) {
 
 	topic := packet.TopicName
 	if !c.CheckTopicAuth(PUB, topic) {
-		log.Error("Pub Topics Auth failed, ", topic)
+		log.Error("Pub Topics Auth failed, ", topic, " clientID = ", c.info.clientID)
 		return
 	}
 
@@ -184,21 +172,21 @@ func (c *client) ProcessPublish(packet *packets.PublishPacket) {
 		puback := packets.NewControlPacket(packets.Puback).(*packets.PubackPacket)
 		puback.MessageID = packet.MessageID
 		if err := c.WriterPacket(puback); err != nil {
-			log.Error("send puback error, ", err)
+			log.Error("send puback error, ", err, " clientID = ", c.info.clientID)
 			return
 		}
 		c.ProcessPublishMessage(packet)
 	case QosExactlyOnce:
 		return
 	default:
-		log.Error("publish with unknown qos")
+		log.Error("publish with unknown qos", " clientID = ", c.info.clientID)
 		return
 	}
 	if packet.Retain {
 		if b := c.broker; b != nil {
 			err := b.rl.Insert(topic, packet)
 			if err != nil {
-				log.Error("Insert Retain Message error: ", err)
+				log.Error("Insert Retain Message error: ", err, " clientID = ", c.info.clientID)
 			}
 		}
 	}
@@ -232,7 +220,7 @@ func (c *client) ProcessPublishMessage(packet *packets.PublishPacket) {
 		if sub != nil {
 			err := sub.client.WriterPacket(packet)
 			if err != nil {
-				log.Error("process message for psub error,  ", err)
+				log.Error("process message for psub error,  ", err, " clientID = ", c.info.clientID)
 			}
 		}
 	}
@@ -258,7 +246,7 @@ func (c *client) ProcessPublishMessage(packet *packets.PublishPacket) {
 				if sub != nil {
 					err := sub.client.WriterPacket(packet)
 					if err != nil {
-						log.Error("send publish error, ", err)
+						log.Error("send publish error, ", err, " clientID = ", c.info.clientID)
 					}
 				}
 
@@ -312,7 +300,7 @@ func (c *client) ProcessSubscribe(packet *packets.SubscribePacket) {
 		t := topic
 		//check topic auth for client
 		if !c.CheckTopicAuth(SUB, topic) {
-			log.Error("Sub topic Auth failed: ", topic)
+			log.Error("Sub topic Auth failed: ", topic, " clientID = ", c.info.clientID)
 			retcodes = append(retcodes, QosFailure)
 			continue
 		}
@@ -359,7 +347,7 @@ func (c *client) ProcessSubscribe(packet *packets.SubscribePacket) {
 		}
 		err := b.sl.Insert(sub)
 		if err != nil {
-			log.Error("Insert subscription error: ", err)
+			log.Error("Insert subscription error: ", err, " clientID = ", c.info.clientID)
 			retcodes = append(retcodes, QosFailure)
 		} else {
 			retcodes = append(retcodes, qoss[i])
@@ -369,7 +357,7 @@ func (c *client) ProcessSubscribe(packet *packets.SubscribePacket) {
 
 	err := c.WriterPacket(suback)
 	if err != nil {
-		log.Error("send suback error, ", err)
+		log.Error("send suback error, ", err, " clientID = ", c.info.clientID)
 		return
 	}
 	//broadcast subscribe message
@@ -381,7 +369,7 @@ func (c *client) ProcessSubscribe(packet *packets.SubscribePacket) {
 	for _, t := range topics {
 		packets := b.rl.Match(t)
 		for _, packet := range packets {
-			log.Info("process retain  message: ", packet)
+			log.Info("process retain  message: ", packet, " clientID = ", c.info.clientID)
 			if packet != nil {
 				c.WriterPacket(packet)
 			}
@@ -432,7 +420,7 @@ func (c *client) ProcessUnSubscribe(packet *packets.UnsubscribePacket) {
 
 	err := c.WriterPacket(unsuback)
 	if err != nil {
-		log.Error("send unsuback error, ", err)
+		log.Error("send unsuback error, ", err, " clientID = ", c.info.clientID)
 		return
 	}
 	// //process ubsubscribe message
@@ -461,7 +449,7 @@ func (c *client) ProcessPing() {
 	resp := packets.NewControlPacket(packets.Pingresp).(*packets.PingrespPacket)
 	err := c.WriterPacket(resp)
 	if err != nil {
-		log.Error("send PingResponse error, ", err)
+		log.Error("send PingResponse error, ", err, " clientID = ", c.info.clientID)
 		return
 	}
 }
@@ -489,7 +477,7 @@ func (c *client) Close() {
 		for _, sub := range subs {
 			err := b.sl.Remove(sub)
 			if err != nil {
-				log.Error("closed client but remove sublist error, ", err)
+				log.Error("closed client but remove sublist error, ", err, " clientID = ", c.info.clientID)
 			}
 		}
 		if c.typ == CLIENT {