Spring MqttPahoMessageDrivenChannelAdapter Lost connection:Connection lost; retrying

Question

We are using Spring message-driven-channel-adapter to subscribe MQTT topic. But we are getting below error very frequently. I have tes

Answer 1

Just wanted to share in case it helps... I had the same exception and fixed it by ensuring a unique client ID was generated (with MqttAsyncClient.generateClientId()), as mentioned here: https://github.com/eclipse/paho.mqtt.java/issues/207#issuecomment-338246879

Answer 2

But you are still not really describing a problem. You show a message above so it must be working for you. Paho is detecting a connection problem; it informs Spring Integration which will reconnect.

You can get complete information about the exception by adding an ApplicationListener to your application.

@Bean
public ApplicationListener<?> eventListener() {
    return new ApplicationListener<MqttConnectionFailedEvent>() {

        @Override
        public void onApplicationEvent(MqttConnectionFailedEvent event) {
            event.getCause().printStackTrace();
        }

    };
}

Result:

Connection lost (32109) - java.io.EOFException
    at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:164)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.EOFException
    at java.io.DataInputStream.readByte(DataInputStream.java:267)
    at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92)
    at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:116)
    ... 1 more

(when I shut down the broker).

If you think there's a problem with the paho client, you should raise an issue for that project.