Question

我正在使用NimbusAPI使用Azure Service Bus。我使用Nimbus从请求/响应操作中获取响应时遇到问题。以下是单元测试的输出。我可以成功获取请求，在断点中逐步执行，并观察它返回响应。客户端，无论是单元测试，MVC应用程序还是其他任何东西，总是超时。下面输出中的倒数第二行显示实际收到了响应，但最后一行表示它不是，并且已经超时。

 12/17/2014 9:42:07 PM -05:00: Constructing bus... 12/17/2014 9:42:08
 PM -05:00: Creating message pumps and subscriptions.
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.RequestResponse.ResponseMessagePumpFactory
 (Nimbus.Infrastructure.RequestResponse.ResponseMessagePumpFactory)
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.MessageSendersAndReceivers.NimbusQueueMessageReceiver
 (inputqueue.myapp.mypc) Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.MessagePump (Nimbus.Infrastructure.MessagePump)
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.NimbusMessagingFactory
 (Nimbus.Infrastructure.NimbusMessagingFactory) Nimbus.GarbageMan:
 Tracking Nimbus.Infrastructure.Commands.CommandMessagePumpsFactory
 (Nimbus.Infrastructure.Commands.CommandMessagePumpsFactory) 12/17/2014
 9:42:08 PM -05:00: Creating command message pumps Nimbus.GarbageMan:
 Tracking
 Nimbus.Infrastructure.RequestResponse.RequestMessagePumpsFactory
 (Nimbus.Infrastructure.RequestResponse.RequestMessagePumpsFactory)
 12/17/2014 9:42:08 PM -05:00: Creating request message pumps
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.RequestResponse.MulticastRequestMessagePumpsFactory
 (Nimbus.Infrastructure.RequestResponse.MulticastRequestMessagePumpsFactory)
 12/17/2014 9:42:08 PM -05:00: Creating multicast request message pumps
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.Events.MulticastEventMessagePumpsFactory
 (Nimbus.Infrastructure.Events.MulticastEventMessagePumpsFactory)
 12/17/2014 9:42:08 PM -05:00: Creating multicast event message pumps
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.Events.CompetingEventMessagePumpsFactory
 (Nimbus.Infrastructure.Events.CompetingEventMessagePumpsFactory)
 12/17/2014 9:42:08 PM -05:00: Creating competing event message pumps
 12/17/2014 9:42:08 PM -05:00: Message pumps and subscriptions are all
 created. 12/17/2014 9:42:08 PM -05:00: Bus built. Job done!
 Nimbus.GarbageMan: Tracking
 Nimbus.Infrastructure.MessageSendersAndReceivers.NimbusQueueMessageSender
 (Nimbus.Infrastructure.MessageSendersAndReceivers.NimbusQueueMessageSender)
 12/17/2014 9:42:08 PM -05:00: Sending request
 Myapp.Messages.DoItRequest to
 q.myapp.messages.doitrequest
 [MessageId:bc1c79cc1965489c84703f5898bd6fd8,
 CorrelationId:bc1c79cc1965489c84703f5898bd6fd8] 12/17/2014 9:42:08 PM
 -05:00: Sent request Myapp.Messages.DoItRequest to q.myapp.messages.doitrequest
 [MessageId:bc1c79cc1965489c84703f5898bd6fd8,
 CorrelationId:bc1c79cc1965489c84703f5898bd6fd8] 12/17/2014 9:42:08 PM
 -05:00: Waiting for response to Myapp.Messages.DoItRequest from
 q.myapp.messages.doitrequest
 [MessageId:bc1c79cc1965489c84703f5898bd6fd8,
 CorrelationId:bc1c79cc1965489c84703f5898bd6fd8] 12/17/2014 9:42:08 PM
 -05:00: Flushing outbound message queue q.myapp.messages.doitrequest (1 messages) 12/17/2014
 9:42:08 PM -05:00: Received response to
 Myapp.Messages.DoItRequest from
 q.myapp.messages.doitrequest
 [MessageId:bc1c79cc1965489c84703f5898bd6fd8,
 CorrelationId:bc1c79cc1965489c84703f5898bd6fd8] in the form of
 System.Threading.Tasks.Task`1[[Myapp.Messages.DoItResponse,
 Myapp.Messages, Version=1.0.0.0, Culture=neutral,
 PublicKeyToken=null]] 12/17/2014 9:42:08 PM -05:00: Fetching existing
 queues... System.TimeoutException : No response was received from the
 bus within the configured timeout. Expected a
 'Myapp.Messages.DoItResponse'.

它说我收到了回复......

9:42:08 PM -05:00: **Received response to
  Myapp.Messages.DoItRequest from
  q.myapp.messages.doitrequest**
  [MessageId:bc1c79cc1965489c84703f5898bd6fd8,
  CorrelationId:bc1c79cc1965489c84703f5898bd6fd8] **in the form of
  System.Threading.Tasks.Task`1[[Myapp.Messages.DoItResponse**,
  Myapp.Messages, Version=1.0.0.0, Culture=neutral,
  PublicKeyToken=null]] 12/17/2014

除了我没有

9:42:08 PM -05:00: Fetching existing
queues... System.TimeoutException : **No response was received from the
bus within the configured timeout. Expected a
'Myapp.Messages.DoItResponse'.**

我有什么遗失的东西需要检查吗？

Answer 1

喔。我的。糟。

似乎我没有致电bus.Start();来实际启动公交车。我创建/配置了总线，这似乎足以发送消息，但显然需要.Start();来实际订阅并注意回复的响应。这解释了为什么我可以在后端中断并看到创建的响应，甚至看到队列中的消息返回，但实际请求从客户端超时。

Answer 2

这很可能是因为调用线程的同步上下文。

要查看同步上下文是什么，请在

上设置监视

System.Threading.Thread.CurrentThread.ExecutionContext.SynchronizationContext

如果它不为空，那么您可能会遇到死锁（请参阅下面文章的链接）。

如果您的测试用例如下所示：

[Test]
public async Task WhenSendingARequestWeShouldReceiveAResponse()
{
    var result = await _bus.Request(new SomeRequest());
    result.ShouldBeOfType<SomeResponse>();
}

然后尝试将其替换为：

[Test]
public async Task WhenSendingARequestWeShouldReceiveAResponse()
{
    var result = await _bus.Request(new SomeRequest()).ConfigureAwait(false);
    result.ShouldBeOfType<SomeResponse>();
}

或者这个：

[Test]
public Task WhenSendingARequestWeShouldReceiveAResponse()
{
    return Task.Run(async () =>
    {
        var result = await _bus.Request(new SomeRequest());
        result.ShouldBeOfType<SomeResponse>();
    }
}

这将帮助您确定是否遇到了死锁或其他问题。

有关同步上下文的更多阅读，请查看http://msdn.microsoft.com/en-us/magazine/gg598924.aspx。顺便说一下，你在任何地方调用.Wait（）对一个返回任务或任务的方法都要求麻烦。

Answer 3

在我的情况下，我使用Environment.MachineName为每个文档创建唯一的实例名称，但忘记了在本地端到端测试期间对其进行更改。原来，在同一台计算机上运行的两个可执行文件的计算机名称是相同的，谁知道呢？

var bus = new BusBuilder().Configure()
    .WithNames("MyApplication", Environment.MachineName) // <-- Problem if running multiple instances on the same machine

NimbusAPI的响应是暂时的，虽然它说收到了

3 个答案: