Reconnect not working after SocketException

[giuliboy]

Our mqtt service is using the MQTTnet ManagedClient which handles auto reconnection. At some point a socketexception occurs ("forcibly closed by remote host" !) which leads to a problem causing the service to crash with 0xc00000fd (STATUS_STACK_OVERFLOW /stack overflow?).

Check the log after the SocketException
@JanEggers get in touch with me if you're bored from factorio ;)

2019-12-17 07:33:54.525 +00:00 [wrn] Timeout while waiting for packet of type 'MqttSubAckPacket'. [MQTTnet.MqttClient]
2019-12-17 07:33:54.529 +00:00 [wrn] Synchronizing subscriptions failed. [MQTTnet.ManagedMqttClient]
MQTTnet.Exceptions.MqttCommunicationTimedOutException: Exception of type 'MQTTnet.Exceptions.MqttCommunicationTimedOutException' was thrown.
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at MQTTnet.PacketDispatcher.MqttPacketAwaiter1.<WaitOneAsync>d__4.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at MQTTnet.Client.MqttClient.<SendAndReceiveAsync>d__461.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at MQTTnet.Client.MqttClient.d__36.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
at MQTTnet.Extensions.ManagedClient.ManagedMqttClient.d__61.MoveNext()
2019-12-17 07:35:11.728 +00:00 [wrn] Communication error while receiving packets. [MQTTnet.MqttClient]
MQTTnet.Exceptions.MqttCommunicationException: An existing connection was forcibly closed by the remote host ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.BeginReceive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags, AsyncCallback callback, Object state)
at System.Net.Sockets.NetworkStream.BeginRead(Byte[] buffer, Int32 offset, Int32 size, AsyncCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at MQTTnet.Implementations.MqttTcpChannel.d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at MQTTnet.Formatter.MqttPacketReader.d__3.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at MQTTnet.Adapter.MqttChannelAdapter.d__37.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at MQTTnet.Adapter.MqttChannelAdapter.d__35.MoveNext()
--- End of inner exception stack trace ---
at MQTTnet.Adapter.MqttChannelAdapter.WrapException(Exception exception)
at MQTTnet.Adapter.MqttChannelAdapter.d__35.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at MQTTnet.Client.MqttClient.d__48.MoveNext()

[JanEggers]

can you reproduce? any SynchronizingSubscriptionsFailedHandler that might trigger a recursion?

[giuliboy]

so far no success on reproduction.

• no SynchronizingSubscriptionsFailedHandler is being used
• our BL relays on ConnectedHandler and MessageReceivedHandler only
  But i noticed that we subscribe to topics everytime we (re)connect. according to https://github.com/chkr1011/MQTTnet/wiki/ManagedClient this is unnecessary. is this harmful and should be avoided?
  (Losing Subscriptions after client disconnect #620)

[chkr1011]

I assume this issue is closed.