Can't create session when the connection is closing

While receiving events using Event Processor Host, from time to time, I’m getting partition receiver exceptions:

System.InvalidOperationException: Can't create session when the connection is closing. at Microsoft.Azure.Amqp.AmqpConnection.AddSession(AmqpSession session, Nullable1 channel) at Microsoft.Azure.Amqp.AmqpCbsLink.OpenCbsRequestResponseLinkAsyncResult.GetAsyncSteps()+MoveNext() — End of stack trace from previous location where exception was thrown — at Microsoft.Azure.Amqp.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.Azure.Amqp.AmqpCbsLink.EndCreateCbsLink(IAsyncResult result) at System.Threading.Tasks.TaskFactory1.FromAsyncCoreLogic(IAsyncResult iar, Func2 endFunction, Action1 endAction, Task1 promise, Boolean requiresSynchronization) — End of stack trace from previous location where exception was thrown — at Microsoft.Azure.Amqp.FaultTolerantAmqpObject1.OnCreateAsync(TimeSpan timeout) at Microsoft.Azure.Amqp.Singleton1.GetOrCreateAsync(TimeSpan timeout) at Microsoft.Azure.Amqp.Singleton1.GetOrCreateAsync(TimeSpan timeout) at Microsoft.Azure.Amqp.TaskHelpers.EndAsyncResult(IAsyncResult asyncResult) at Microsoft.Azure.Amqp.IteratorAsyncResult1.StepCallback(IAsyncResult result) — End of stack trace from previous location where exception was thrown — at Microsoft.Azure.Amqp.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.Azure.Amqp.AmqpCbsLink.<>c__DisplayClass4_0.<SendTokenAsync>b__1(IAsyncResult a) at System.Threading.Tasks.TaskFactory1.FromAsyncCoreLogic(IAsyncResult iar, Func2 endFunction, Action1 endAction, Task1 promise, Boolean requiresSynchronization) — End of stack trace from previous location where exception was thrown — at Microsoft.Azure.EventHubs.Amqp.AmqpPartitionReceiver.CreateLinkAsync(TimeSpan timeout) at Microsoft.Azure.Amqp.FaultTolerantAmqpObject1.OnCreateAsync(TimeSpan timeout) at Microsoft.Azure.Amqp.Singleton1.GetOrCreateAsync(TimeSpan timeout) at Microsoft.Azure.Amqp.Singleton1.GetOrCreateAsync(TimeSpan timeout) at Microsoft.Azure.EventHubs.Amqp.AmqpPartitionReceiver.OnReceiveAsync(Int32 maxMessageCount, TimeSpan waitTime) at Microsoft.Azure.EventHubs.Amqp.AmqpPartitionReceiver.OnReceiveAsync(Int32 maxMessageCount, TimeSpan waitTime) at Microsoft.Azure.EventHubs.PartitionReceiver.ReceiveAsync(Int32 maxMessageCount, TimeSpan waitTime) at Microsoft.Azure.EventHubs.Amqp.AmqpPartitionReceiver.ReceivePumpAsync(CancellationToken cancellationToken, Boolean invokeWhenNoEvents)

There is an open issue related to this in azure-amqp sdk github repo https://github.com/Azure/azure-amqp/issues/140), but one of the team members is suggesting that:

This exception is expected when a session is to be created but the connection is closing. Typically the session creation is a result of an API call from the upper SDK and should be handled by the SDK as a communication error. Please report the error to the SDKs you are using so it can be handled correctly by the retry policy in the SDKs.

[serkantkaraca]

Fix will ship in 4.3.1 release soon.

[serkantkaraca]

I have sent a PR to convert this exception to retriable error.