过期时间过后，Azure Service Bus队列中的消息仍保留在队列中

Question

I'm working with Azure Service Bus Queues in a request/response pattern using two queues and in general it is working well. I'm using pretty simple code from some good examples I've found. My queues are between web and worker roles, using MVC4, Visual Studio 2012 and .NET 4.5.

During some stress testing, I end up overloading my system and some responses are not delivered before the client gives up (which I will fix, not the point of this question).

When this happens, I end up with many messages left in my response queue, all well beyond their ExpiresAtUtc time. My message TimeToLive is set for 5 minutes.

When I look at the properties for a message still in the queue, it is clearly set to expire in the past, with a TimeToLive of 5 minutes.

I create the queues if they don't exist with the following code:

namespaceManager.CreateQueue(
                    new QueueDescription( RequestQueueName )
                    {
                        RequiresSession = true,
                        DefaultMessageTimeToLive = TimeSpan.FromMinutes( 5 ) // messages expire if not handled within 5 minutes
                    } );

What would cause a message to remain in a queue long after it is set to expire?

Answer 1

据我了解，没有后台进程可以清除这些消息，只有通过调用Receive向前移动队列光标的操作才会导致服务器跳过并处理过期的消息，并实际上返回第一个消息。未过期，或如果所有都过期，则不过期。