Client keeps on disconnecting and reconnecting

[arpitkh96]

Please fill out the form below before submitting, thank you!

• Bug exists Release Version 1.1.0 ( Master Branch)
• Bug exists in Snapshot Version 1.1.1-SNAPSHOT (Develop Branch)

Here's the class

public class MessageReciever implements MqttCallbackExtended {

    Gson gson;
    static String subscribeTopic;
    static MessageReciever m = new MessageReciever();
    static MqttClient sampleClient;

    static void subscribe(String topic, String clientId) {
        int qos = 2;
        subscribeTopic = topic;
        try {
            if (sampleClient == null) {
                sampleClient = new MqttClient(broker, clientId, new MemoryPersistence());
            }

        System.out.println("Connecting");
            MqttConnectOptions connOpts = new MqttConnectOptions();
            connOpts.setCleanSession(true);
            connOpts.setAutomaticReconnect(true);
            sampleClient.setCallback(m);
            sampleClient.connect(connOpts);
        System.out.println("Connected");
        } catch (MqttException me) {
            me.printStackTrace();
        }
    }

    @Override
    public void connectionLost(Throwable thrwbl) {
        System.out.println("Connection lost ");

    }

    @Override
    public void messageArrived(String string, MqttMessage mm) throws Exception {
        System.out.println("Message " + mm.toString() + "\n" + string);
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken imdt) {

    }

    @Override
    public void connectComplete(boolean bln, String string) {
        System.out.println("On Connection Complete");
        try {
            sampleClient.subscribe(subscribeTopic, 2);
        } catch (MqttException ex) {
            Logger.getLogger(MessageReciever.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}

Logs after calling subscribe() once

Connecting
On Connection Complete
Connected
Connection lost 
On Connection Complete
Connection lost 
On Connection Complete
Connection lost 
On Connection Complete
goes on and on..

[miketran78727]

I cannot reproduce the problem.. Perhaps, you can explain the steps in more details.. I copied your code and changed it little bit as follows:

package autoconnect.test;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallbackExtended;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;


public class MessageReceiver implements MqttCallbackExtended {

    String broker;
    String clientId;
    String subscribeTopic;
    MqttClient client = null;

    MessageReceiver(String broker, String clientId, String subscribeTopic) {
        this.broker = broker;
        this.clientId = clientId;
        this.subscribeTopic = subscribeTopic;
    }

    void subscribe() {

        try {
            if (client == null) {
                client = new MqttClient(broker, clientId, new MemoryPersistence());
            }

            System.out.println("Connecting");
            MqttConnectOptions connOpts = new MqttConnectOptions();
            connOpts.setKeepAliveInterval(10);
            connOpts.setCleanSession(true);
            connOpts.setAutomaticReconnect(true);
            client.setCallback(this);
            client.connect(connOpts);
            System.out.println("Connected");

        } catch (MqttException me) {
            me.printStackTrace();
        }
    }

    void quit() {
        final String METHOD = "quit";
        try {
            client.disconnect();
            System.out.println(METHOD + " disconnected!");
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void connectionLost(Throwable thrwbl) {
        System.out.println("Connection lost ");

    }

    @Override
    public void messageArrived(String string, MqttMessage mm) throws Exception {
        System.out.println("Message " + mm.toString() + "\n" + string);
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken imdt) {

    }

    @Override
    public void connectComplete(boolean bReconnect, String host) {
        final String METHOD = "connectComplete";
        System.out.println(METHOD + " Connected to " + host + " Auto reconnect ? " + bReconnect);
        try {
            client.subscribe(subscribeTopic, 2);
        } catch (MqttException ex) {
            ex.printStackTrace();
        }
    }
}

The test program:

package autoconnect.test;

public class test01 {

    public static void main(String[] args) {
        String broker = "tcp://messagesight.demos.ibm.com:1883";
        String clientId = "abc012345";
        String subscribeTopic = "/test1";

        System.out.println("START TEST");

        MessageReceiver m = new MessageReceiver(broker, clientId, subscribeTopic);

        m.subscribe();

        try {
            Thread.sleep(120000);
            m.quit();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        System.out.println("END TEST");
        System.exit(0);

    }

}

The console shows that auto-reconnect was triggered and worked as expected:

START TEST
Connecting
connectComplete Connected to tcp://messagesight.demos.ibm.com:1883 Auto reconnect ? false
Connected
Sep 05, 2016 1:38:22 AM org.eclipse.paho.client.mqttv3.internal.ClientState checkForActivity
SEVERE: abc012345: Timed out as no activity, keepAlive=10,000 lastOutboundActivity=1,473,035,892,885 lastInboundActivity=1,473,035,882,922 time=1,473,035,902,885 lastPing=1,473,035,892,885
Connection lost 
connectComplete Connected to tcp://messagesight.demos.ibm.com:1883 Auto reconnect ? true
quit disconnected!
END TEST

[arpitkh96]

Yours worked.No idea why mine didn't.

[arpitkh96]

it just appeared again in android too

public class MainActivity extends AppCompatActivity implements VolleyInterface{
    /*Removed Code*/
MqttClient client = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        /*Removed Code*/
        subscribe();
    }

    public void subscribe() {

        try {
            if (client == null) {
                client = new MqttClient(URL_API.mqtt_broker, Utils.getdeviceId(this), new MemoryPersistence());
            }

            System.out.println("Connecting");
            MqttConnectOptions connOpts = new MqttConnectOptions();
            connOpts.setKeepAliveInterval(10);
            connOpts.setCleanSession(true);
            connOpts.setAutomaticReconnect(true);
            client.setCallback(new MqttCallbackExtended() {
                @Override
                public void connectComplete(boolean bReconnect, String host) {
                    final String METHOD = "connectComplete";

                    System.out.println(METHOD + subscribeTopic+" Connected to " + host + " Auto reconnect ? " + bReconnect);
                    try {
                        client.subscribe(subscribeTopic, 0);
                    } catch (MqttException ex) {
                        ex.printStackTrace();
                    }
                }
                @Override
                public void connectionLost(Throwable thrwbl) {
                    System.out.println("Connection lost ");
                }


                @Override
                public void messageArrived(String string, MqttMessage mm) throws Exception {
                    System.out.println(mm.toString());
                    /*Removed Code*/

                }

                @Override
                public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {

                }
            });
            client.connect(connOpts);
            System.out.println("Connected");

        } catch (MqttException me) {
            me.printStackTrace();
        }
    }

    void quit() {
        final String METHOD = "quit";
        try {
            client.disconnect();
            System.out.println(METHOD + " disconnected!");
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        quit();
    }
}

logs

 I/System.out:Connecting
 I/System.out: connectComplete/status/arpitkh96 Connected to "url" Auto reconnect ? false
I/System.out: Connected
I/System.out: /*My MQTT message*/
I/System.out: Connection lost 
I/System.out: connectComplete/status/arpitkh96 Connected to"url" Auto reconnect ? true
I/System.out:/*My MQTT message*/

Goes on and on
PS - The message is a retained

[miketran78727]

Are you using the same clientId in any other threads/process?

[arpitkh96]

Well..I am using device ID of phone as client Id so that's not possible.. It's only one device.And I tried changing client I'd and even broker... None helps

[miketran78727]

The publisher is not on the same device, correct?

[arpitkh96]

Yea it's different. Can I do something here to see broker stats or something?

[arpitkh96]

Nvm.Its fixed. It was because i was running some ui thread code in 'onMessageArrived' . Though that should have raised exception

[vyshakhkj]

I had a the issue of keeps on connecting and reconnecting on connection loss. I was doing like, if connectionLost() method in MqttCallback class is called I will call mqttClient.connect(). This will end in a loop. So instead of calling mqttClient.connect(), I called mqttClient.reconnect(); and the issue fixed.

[francescovgg]

Hi everyone,
I'm facing a similar problem of frequent connection loss.
I'm using the pahho-mqtt C library on a linux gateway connected via GMS to the Microsoft IoT HuB (working as a broker).

On certain gateways, there are frequent connectionLost() callbacks (every few minutes). Inside the connectionLost() I simply raise a flag which is then read by the main thread application in order to perform a new MQTT connection. After the MQTT connection is performed succesfully, the connectionLost() is immediately called again.

void onConnectionLost(void *context, char *cause) { gAppLog.PrintLog(LOG_DEBUG_WS, "MQTT Connection lost: %s ", cause); gCloudHdl.bMQTTConnected = false; }
the "cause" string returns (null). In the main thread there is something similar to

if(!gCloudHdl.bMQTTConnected) {MQTTAsync_create(...); MQTTAsync_setCallbacks(...); MQTTAsync_connect(...); }

Any suggestions? Many thanks in advance.
Francesco