I'm working on an Android app using Eclipse Paho's MqttAsyncClient (In Android) with SSL and multiple broker IPs. The idea is to that some nodes can be died and multiple IPs should improve system reability:

  fun connect() {
      val sslContext = settingsUseCase.getSSLContext() ?: return
      val brokerIPs = settingsUseCase.getBrokerIPs()
      val clientUID = settingsUseCase.getUID() ?: return
  
      if (brokerIPs.isEmpty()) return
  
      mqttClient = MqttAsyncClient(brokerIPs.random(), clientUID, MemoryPersistence()).apply {
          setCallback(MqttCallbacks())
          connect(
              MQTTUtils.getSSLMQTTOptions(sslContext, brokerIPs),
              null,
              MqttConnectListener()
          )
      }
  }

The SSL options look like this:

fun getSSLMQTTOptions(
    sslContext: SSLContext,
    serverURIs: Array<String>
): MqttConnectOptions {
    val sslSocketFactory = sslContext.socketFactory

    return MqttConnectOptions().apply {
        isAutomaticReconnect = true
        isCleanSession = false
        connectionTimeout = 60
        keepAliveInterval = 120
        mqttVersion = MqttConnectOptions.MQTT_VERSION_3_1_1
        socketFactory = sslSocketFactory
        serverURIs = serverURIs
    }
}

Problem

Sometimes the client connects to a broken node. When this happens:

• The connection hangs silently — no logs from connectionLost() or connectComplete().
• connectionTimeout appears to have no effect; the process is stuck indefinitely.
• disconnect(), close(), and reconnect() all result in an "Already connected" exception.
• Only disconnectForcibly() doesn't cause an exception, but does nothing.
• The only workaround is physically disabling the network (e.g. turning off Wi-Fi), which finally forces a disconnect.

Question

Is there a reliable way to forcefully cancel or kill the MqttAsyncClient when it's stuck like this?

Ideally I’d want to do one of the following:

• Cancel the pending connection attempt.
• Retry with a different IP.
• Forcefully reset the client state.

Any suggestions or known issues with Paho’s MqttAsyncClient in this context?

What I've tried

• mqttClient?.disconnectForcibly()
• Rebuilding a new MqttAsyncClient instance (still hangs if previous connection is stuck)
• Setting smaller connectionTimeout (ignored)