diff --git a/config/config.go b/config/config.go
index 13f8f16..9b2ea48 100644
--- a/config/config.go
+++ b/config/config.go
@@ -173,12 +173,12 @@ func (sc *SafeConfig) ReloadConfig(confFile string) (err error) {
 		if probe.ClientID == "" {
 			hostname, _ := os.Hostname()
 			hostname = strings.Replace(hostname, ".", "-", -1)
-			probe.ClientID = "emqx-exporter-probe-" + hostname + fmt.Sprintf("%d", index)
+			probe.ClientID = fmt.Sprintf("emqx-exporter-probe-%s-%d", hostname, index)
 		}
 		if probe.Topic == "" {
 			hostname, _ := os.Hostname()
 			hostname = strings.Replace(hostname, ".", "-", -1)
-			probe.Topic = "emqx-exporter-probe/" + hostname + "/" + fmt.Sprintf("%d", index)
+			probe.Topic = fmt.Sprintf("emqx-exporter-probe/%s/%d", hostname, index)
 		}
 		if probe.KeepAlive == 0 {
 			probe.KeepAlive = 30
diff --git a/main_test.go b/main_test.go
index 2c0d98e..95b93ad 100644
--- a/main_test.go
+++ b/main_test.go
@@ -460,6 +460,7 @@ dashboard {
 		}
 	}
 }
+log.console.level = debug
 listeners {
 	tcp.fake{
 		bind = 11883
@@ -590,7 +591,7 @@ rule_engine {
 
 	mqttxSubResp, err := cli.ContainerCreate(ctx, &container.Config{
 		Image: mqttxContainer.image,
-		Cmd:   []string{"mqttx", "bench", "sub", "-t", "test", "-h", emqxInfo.NetworkSettings.IPAddress},
+		Cmd:   []string{"mqttx", "sub", "-t", "test", "-h", emqxInfo.NetworkSettings.IPAddress},
 	}, nil, nil, nil, "mqttx-sub")
 	if err != nil {
 		panic(err)
@@ -602,7 +603,7 @@ rule_engine {
 
 	mqttxPubResp, err := cli.ContainerCreate(ctx, &container.Config{
 		Image: mqttxContainer.image,
-		Cmd:   []string{"mqttx", "bench", "pub", "-c", "1", "-t", "test", "-h", emqxInfo.NetworkSettings.IPAddress},
+		Cmd:   []string{"mqttx", "pub", "-c", "1", "-t", "test", "-h", emqxInfo.NetworkSettings.IPAddress},
 	}, nil, nil, nil, "mqttx-pub")
 	if err != nil {
 		panic(err)
diff --git a/prober/mqtt.go b/prober/mqtt.go
index b8a572f..6403bc8 100644
--- a/prober/mqtt.go
+++ b/prober/mqtt.go
@@ -3,6 +3,7 @@ package prober
 import (
 	"context"
 	"emqx-exporter/config"
+	"fmt"
 	"sync"
 	"time"
 
@@ -49,6 +50,7 @@ func init() {
 }
 
 func initMQTTProbe(probe config.Probe, logger log.Logger) (*MQTTProbe, error) {
+	var isReady = make(chan struct{})
 	var msgChan = make(chan mqtt.Message)
 
 	opt := mqtt.NewClientOptions().AddBroker(probe.Scheme + "://" + probe.Target)
@@ -60,7 +62,8 @@ func initMQTTProbe(probe config.Probe, logger log.Logger) (*MQTTProbe, error) {
 		opt.SetTLSConfig(probe.TLSClientConfig.ToTLSConfig())
 	}
 	opt.SetOnConnectHandler(func(c mqtt.Client) {
-		level.Info(logger).Log("msg", "Connected to MQTT broker", "target", probe.Target)
+		optReader := c.OptionsReader()
+		level.Info(logger).Log("msg", "Connected to MQTT broker", "target", probe.Target, "client_id", optReader.ClientID())
 		token := c.Subscribe(probe.Topic, probe.QoS, func(c mqtt.Client, m mqtt.Message) {
 			msgChan <- m
 		})
@@ -69,6 +72,7 @@ func initMQTTProbe(probe config.Probe, logger log.Logger) (*MQTTProbe, error) {
 			level.Error(logger).Log("msg", "Failed to subscribe to MQTT topic", "target", probe.Target, "topic", probe.Topic, "qos", probe.QoS, "err", token.Error())
 			return
 		}
+		isReady <- struct{}{}
 		level.Info(logger).Log("msg", "Subscribed to MQTT topic", "target", probe.Target, "topic", probe.Topic, "qos", probe.QoS)
 	})
 	opt.SetConnectionLostHandler(func(c mqtt.Client, err error) {
@@ -80,6 +84,12 @@ func initMQTTProbe(probe config.Probe, logger log.Logger) (*MQTTProbe, error) {
 		return nil, token.Error()
 	}
 
+	select {
+	case <-isReady:
+	case <-time.After(60 * time.Second):
+		return nil, fmt.Errorf("MQTT probe connect timeout")
+	}
+
 	return &MQTTProbe{
 		Client:  c,
 		MsgChan: msgChan,
@@ -102,6 +112,7 @@ func ProbeMQTT(probe config.Probe, logger log.Logger) bool {
 		return false
 	}
 
+	level.Info(logger).Log("msg", "Publishing MQTT message", "target", probe.Target, "topic", probe.Topic, "qos", probe.QoS)
 	if token := mqttProbe.Client.Publish(probe.Topic, probe.QoS, false, "hello world"); token.Wait() && token.Error() != nil {
 		return false
 	}