SignalR Websocket exception on client close

Question

When starting and stopping the SignalR client, which is connected to the main stand-alone server, for example:

async public void Start(string url) { _connection = new HubConnection(url); _proxy = _connection.CreateHubProxy("hubname"); await _connection.Start().ContinueWith((task) => IsRunning = true); } public void Stop() { _connection.Stop(); } 

I get the following exception when calling the "Stop" method (including trace messages):

 SignalR.Transports.TransportHeartBeat Verbose: 0 : KeepAlive(c75fe282-a86d-406a-935b-5981b47bd472) SignalR.Transports.TransportHeartBeat Information: 0 : Connection 1bdabc19-e0a7-4649-aabb-bade071ad6d0 is New. SignalR.Transports.WebSocketTransport Information: 0 : Abort(1bdabc19-e0a7-4649-aabb-bade071ad6d0) SignalR.Transports.TransportHeartBeat Information: 0 : Removing connection 1bdabc19-e0a7-4649-aabb-bade071ad6d0 SignalR.Transports.WebSocketTransport Information: 0 : End(1bdabc19-e0a7-4649-aabb-bade071ad6d0) SignalR.Transports.WebSocketTransport Verbose: 0 : DrainWrites(1bdabc19-e0a7-4649-aabb-bade071ad6d0) SignalR.Transports.WebSocketTransport Information: 0 : CloseSocket(1bdabc19-e0a7-4649-aabb-bade071ad6d0) App.vshost.exe Error: 0 : Error while closing the websocket: System.Net.WebSockets.WebSocketException (0x80004005): An internal WebSocket error occurred. Please see the innerException, if present, for more details. ---> System.Net.Sockets.SocketException (0x80004005): An existing connection was forcibly closed by the remote host at System.Net.WebSockets.WebSocketConnectionStream.WebSocketConnection.WriteAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken) at System.Net.WebSockets.WebSocketConnectionStream.<WriteAsync>d__11.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.Net.WebSockets.WebSocketBase.<SendFrameAsync>d__11.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.Net.WebSockets.WebSocketBase.WebSocketOperation.<Process>d__47.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.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>d__17.MoveNext() at System.Net.WebSockets.WebSocketBase.ThrowIfConvertibleException(String methodName, Exception exception, CancellationToken cancellationToken, Boolean aborted) at System.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>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 Microsoft.AspNet.SignalR.WebSockets.WebSocketHandler.<<CloseAsync>b__6>d__8.MoveNext() App.vshost.exe Error: 0 : Error while closing the websocket: System.Net.WebSockets.WebSocketException (0x80004005): An internal WebSocket error occurred. Please see the innerException, if present, for more details. ---> System.Net.Sockets.SocketException (0x80004005): An existing connection was forcibly closed by the remote host at System.Net.WebSockets.WebSocketConnectionStream.WebSocketConnection.WriteAsync(Byte[] buffer, Int32 offset, Int32 count, CancellationToken cancellationToken) at System.Net.WebSockets.WebSocketConnectionStream.<WriteAsync>d__11.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.Net.WebSockets.WebSocketBase.<SendFrameAsync>d__11.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.Net.WebSockets.WebSocketBase.WebSocketOperation.<Process>d__47.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.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>d__17.MoveNext() at System.Net.WebSockets.WebSocketBase.ThrowIfConvertibleException(String methodName, Exception exception, CancellationToken cancellationToken, Boolean aborted) at System.Net.WebSockets.WebSocketBase.<CloseOutputAsyncCore>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 Microsoft.AspNet.SignalR.WebSockets.WebSocketHandler.<<CloseAsync>b__6>d__8.MoveNext() SignalR.Transports.WebSocketTransport Information: 0 : CompleteRequest (1bdabc19-e0a7-4649-aabb-bade071ad6d0) SignalR.Transports.TransportHeartBeat Verbose: 0 : KeepAlive(c75fe282-a86d-406a-935b-5981b47bd472) SignalR.Transports.TransportHeartBeat Verbose: 0 : KeepAlive(c75fe282-a86d-406a-935b-5981b47bd472) 

It seems that the settings themselves are working fine, and the devices can connect, send, receive, and disconnect. But with every shutdown, I get a terrible exception. Any ideas what could be the problem? I am using SignalR 2.2.0 and Owin 1.2.2.

Answer 1

It seems like a known issue that can be fixed in v3.

Answer 2

Try providing a TimeSpan for the close method to give time to actually close while waiting for any asynchronous processes that may be running:

 public void Stop() { _connection.Stop(new TimeSpan(1000)); } 

It worked for me.

Answer 3

Ok guys, I know him lame. I try to turn off the signalr client when the mainwindow closes, and I get a lot of exceptions that I cannot catch, and my process freezes. So I decided to kill the main process in form.

 private void OnClose(object sender, CancelEventArgs e){ try { var process = Process.GetCurrentProcess(); process.Kill(); //HubConnection.Stop(); } catch (Exception ex) { Console.WriteLine(ex); } } 

Answer 4

I solved this problem with

 connection.Reconnecting += connection.Stop; 

Because I found that the connection status is always reconnecting

Answer 5

If I understand correctly, you want to stop sending a message when the client is disconnected. So my approach is to use connection life events in SignalR. This is the official page: SignalRLifeTimeEvents

 public override System.Threading.Tasks.Task OnDisconnected() { //-- When any client will close the browser or page this event will fire return base.OnDisconnected(); }