IOException in TryPingAsync

[bgrainger]

A customer reported this issue:

System.IO.IOException: Unable to write data to the transport connection: An established connection was aborted by the software in your host machine. ---> System.Net.Sockets.SocketException: An established connection was aborted by the software in your host machine
   at System.Net.Sockets.Socket.Send(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
   --- End of inner exception stack trace ---
   at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.Security._SslStream.StartWriting(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security._SslStream.ProcessWrite(Byte[] buffer, Int32 offset, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslStream.Write(Byte[] buffer, Int32 offset, Int32 count)
   at MySql.Data.Protocol.Serialization.StreamByteHandler.WriteBytesAsync(ArraySegment`1 data, IOBehavior ioBehavior)
   at MySql.Data.Protocol.Serialization.ProtocolUtility.WritePacketAsync(IByteHandler byteHandler, Int32 sequenceNumber, ArraySegment`1 contents, IOBehavior ioBehavior)
   at MySql.Data.Protocol.Serialization.ProtocolUtility.WritePayloadAsync(IByteHandler byteHandler, Func`1 getNextSequenceNumber, ArraySegment`1 payload, IOBehavior ioBehavior)
   at MySql.Data.Protocol.Serialization.StandardPayloadHandler.WritePayloadAsync(ArraySegment`1 payload, IOBehavior ioBehavior)
   at MySql.Data.Serialization.MySqlSession.SendReplyAsync(PayloadData payload, IOBehavior ioBehavior, CancellationToken cancellationToken)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MySql.Data.Serialization.MySqlSession.TryAsyncContinuation(Task`1 task)
   at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
   at System.Threading.Tasks.Task.Execute()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.ConfiguredValueTaskAwaitable`1.ConfiguredValueTaskAwaiter.GetResult()
   at MySql.Data.Serialization.MySqlSession.<TryPingAsync>d__51.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MySql.Data.MySqlClient.ConnectionPool.<GetSessionAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MySql.Data.MySqlClient.MySqlConnection.<CreateSessionAsync>d__66.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MySql.Data.MySqlClient.MySqlConnection.<OpenAsync>d__17.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at MySql.Data.MySqlClient.MySqlConnection.Open()

A simple fix for this exception would be to catch IOException in TryPingAsync; however, it would be good to know why this is happening (because failure to retrieve a connection from the pool will reduce its effectiveness).

[bgrainger]

I couldn't reproduce the problem in a local stress test (against the same DB server).

[caleblloyd]

Yes, we do need to catch IOException. Already added in the netstandard2.0 branch at 6e4eb0a#diff-709a9503470224e906bdecb8736e16c4R328

I think this comment was about this, StreamByteHandler throws EndOfStreamException when a connection was interrupted on Linux but it throws IOException on Windows I believe

[bgrainger]

Fixed in 0.22.0.