Azure EventHub发件人无法发送邮件(Azure EventHub sender fails to send messages)

我使用最新的WindowsAzure.ServiceBus nuget包和简单的代码片段从我的Cloud Service WebRole api控制器向Azure EventHub发送消息：

var eventData = new EventData(buffer) { PartitionKey = partition }; await _eventHubClient.SendAsync(eventData);

过了一会儿，发件人无法发送邮件，每次我尝试发送邮件时都会在日志中看到以下异常：

Microsoft.ServiceBus.Messaging.MessagingCommunicationException: An error occurred during communication with 'N/A'. Check the connection information, then retry. ---> System.InvalidOperationException: Failed with error code 0xe. Server stack trace: at Microsoft.ServiceBus.Tracing.EventSource..ctor(Boolean disableTracing) at Microsoft.ServiceBus.Tracing.MessagingClientEtwProvider.get_Provider() at Microsoft.ServiceBus.Messaging.Amqp.Sasl.SaslTransportProvider.AddHandler(SaslHandler handler) at Microsoft.ServiceBus.Messaging.Amqp.AmqpTransportSettings.CreateAmqpSettings(String sslHostName, Int32 maxFrameSize, Boolean forceTokenProvider) at Microsoft.ServiceBus.Messaging.Amqp.AmqpMessagingFactory.ConnectAsyncResult.<GetAsyncSteps>d__13.MoveNext() at Microsoft.ServiceBus.Messaging.IteratorAsyncResult`1.EnumerateSteps(CurrentThreadType state) at Microsoft.ServiceBus.Messaging.IteratorAsyncResult`1.Start() Exception rethrown at [0]: at Microsoft.ServiceBus.Common.ExceptionDispatcher.Throw(Exception exception) at Microsoft.ServiceBus.Common.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.ServiceBus.Messaging.Amqp.AmqpMessagingFactory.ConnectAsyncResult.End(IAsyncResult result, ConnectInfo& info) at Microsoft.ServiceBus.Messaging.Amqp.FaultTolerantObject`1.CreateAsyncResult.<>c.<GetAsyncSteps>b__5_1(CreateAsyncResult thisPtr, IAsyncResult r) at Microsoft.ServiceBus.Messaging.IteratorAsyncResult`1.EnumerateSteps(CurrentThreadType state) Exception rethrown at [1]: at Microsoft.ServiceBus.Common.ExceptionDispatcher.Throw(Exception exception) at Microsoft.ServiceBus.Common.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.ServiceBus.Messaging.Amqp.FaultTolerantObject`1.OnEndCreateInstance(IAsyncResult asyncResult) at Microsoft.ServiceBus.Messaging.SingletonManager`1.EndGetInstance(IAsyncResult asyncResult) at Microsoft.ServiceBus.Messaging.Amqp.AmqpMessagingFactory.OpenLinkAsyncResult.<>c.<GetAsyncSteps>b__35_3(OpenLinkAsyncResult thisPtr, IAsyncResult r) at Microsoft.ServiceBus.Messaging.IteratorAsyncResult`1.EnumerateSteps(CurrentThreadType state) --- End of inner exception stack trace --- at Microsoft.ServiceBus.Common.ExceptionDispatcher.Throw(Exception exception) at Microsoft.ServiceBus.Common.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.ServiceBus.Messaging.Amqp.FaultTolerantObject`1.OnEndCreateInstance(IAsyncResult asyncResult) at Microsoft.ServiceBus.Messaging.SingletonManager`1.EndGetInstance(IAsyncResult asyncResult) at Microsoft.ServiceBus.Messaging.Amqp.AmqpMessageSender.OnEndOpen(IAsyncResult result) at Microsoft.ServiceBus.Messaging.ClientEntity.EndOpen(IAsyncResult result) at Microsoft.ServiceBus.Messaging.OpenOnceManager.OnEndCreateInstance(IAsyncResult asyncResult) at Microsoft.ServiceBus.Messaging.SingletonManager`1.EndGetInstance(IAsyncResult asyncResult) at Microsoft.ServiceBus.Messaging.OpenOnceManager.OpenOnceManagerAsyncResult`1.OpenComplete(IAsyncResult result) at Microsoft.ServiceBus.Messaging.OpenOnceManager.OpenOnceManagerAsyncResult`1..ctor(OpenOnceManager openOnceManager, TimeSpan openTimeout, AsyncCallback callback, Object state, Func`3 beginOperation, EndOperation`1 endOperation) at Microsoft.ServiceBus.Messaging.OpenOnceManager.Begin(AsyncCallback callback, Object state, Func`3 beginOperation, Action`1 endOperation) at Microsoft.ServiceBus.Messaging.MessageSender.BeginSendEventData(TrackingContext trackingContext, IEnumerable`1 eventDatas, TimeSpan timeout, AsyncCallback callback, Object state) at Microsoft.ServiceBus.Messaging.EventHubClient.<>c__DisplayClass32_0.<SendAsync>b__0(AsyncCallback c, Object s) at System.Threading.Tasks.TaskFactory`1.FromAsyncImpl(Func`3 beginMethod, Func`2 endFunction, Action`1 endAction, Object state, TaskCreationOptions creationOptions) at Microsoft.ServiceBus.Common.Parallel.TaskHelpers.CreateTask(Func`3 begin, Action`1 end, Object state) --- 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)

似乎一旦发件人绊倒这个错误，它不能再发送消息。

I use latest WindowsAzure.ServiceBus nuget package and simple code snippet to send messages to Azure EventHub from my Cloud Service WebRole api controller:

var eventData = new EventData(buffer) { PartitionKey = partition }; await _eventHubClient.SendAsync(eventData);

After a while, sender fails to send messages and I see following exceptions in logs every time I try to send a message:

Seems once sender stumble upon this error it can't send messages anymore.