带有WCF和持久队列的RabbitMQ

Question

I am trying to write a wcf service that works over the rabbitMQ binding. I was able to successfully create a server and a client and have the client send messages to the server via the queue. I am confused about 2 issues.

1. As soon as the service is shutdown the queue is deleted. Is there a way to configure wcf and rabbitMQ so that the queue is persistent? This way I dont have to worry about losing data if my server crashes.

2. I can't seem to control the name of the queue. When I run rabbitmqctl.bat list_queues I see that the queue is called amq.gen-3IgZD30XvTEQWNRsezSUUA== . Is there a way to control the name of the queue?

Answer 1

That cannot be done with the WCF bindings. See this mailing list thread for details.

Basically, you cannot control the queue name via WCF, which means you are limited to anonymous queues (like the one you are seeing), which, in turn, means that you can only use non-persistent queues.

If you need more control than is offered by the WCF bindings, you should consider using the full .NET client. It's quite easy to use, and there are a bunch of tutorials to help you get started (they are in Java, but the .NET API is very similar).

Answer 2

I had the same problem as you did and what I did was to edit the source code of the rabbitMQDotNetClient.

File: RabbitMQInputChannel.cs

    public override void Open(TimeSpan timeout)
    {            
        if (State != CommunicationState.Created && State != CommunicationState.Closed)
            throw new InvalidOperationException(string.Format("Cannot open the channel from the {0} state.", base.State));

        OnOpening();
#if VERBOSE
        DebugHelper.Start();
#endif
        //Create a queue for messages destined to this service, bind it to the service URI routing key
#if USE_DEFINED_QUEUE_NAMES
        //here we create a queue that uses the name given in the service address in the wcf binding.
        //if the address in the web.config is: soap.amq:///QueueName
        //the name of the queue will be: QueueName
        //LVV
        string queue = m_model.QueueDeclare(base.LocalAddress.Uri.PathAndQuery, true, false, false, null);
#else
        string queue = m_model.QueueDeclare();
#endif
        m_model.QueueBind(queue, Exchange, base.LocalAddress.Uri.PathAndQuery, null);

        //Listen to the queue
        m_messageQueue = new QueueingBasicConsumer(m_model);
        m_model.BasicConsume(queue, false, m_messageQueue);

#if VERBOSE
        DebugHelper.Stop(" ## In.Channel.Open {{\n\tAddress={1}, \n\tTime={0}ms}}.", LocalAddress.Uri.PathAndQuery);
#endif
        OnOpened();
    }

Compile with the flag USE_DEFINED_QUEUE_NAMES. This will create a queue name with the name you have given in your app.config or web.config file. You can always change the queues options on the QueueDeclare(...) if you want your queues to behave differently than the ones I'm creating. Cheers!