WCF MSMQ binding with an IIS service – how to instantiate the service

iismsmqmsmq-wcfwcf

I have a WCF service with netMsmqBinding. My client can send messages to my queue, and when the service is running it retrieves messages from the queue as expected. If the service is not running, messages received are queued until the service starts.

My problem is that the service does not start when a message hits the queue. The service is hosted in IIS, and so it is not instantiated until IIS receives a request. If I browse to the service then it processes the messages in the queue, but obviously this is not my desired method of processing the queue!

I expect that I need to change the service implementation, or change the IIS setup, but I do not know where or what to change.

UPDATE

Does anyone actually use MSMQ over WCF? I had this working for a short time – I enabled the binding on a different website on the same server, bizarrely – but now it has somehow stopped working again.

The only problem I am having is with the Activation of the service when there is a message in the queue. At present the queue only processes when the service is instantiated, e.g. when I browse the the .svc file. I have the net.msmq protocol enabled on the application, and I have the net.msmq binding enabled on the site… is there anything else I need to do?

Best Answer

You explicitly need to configure IIS for non HTTP activation. I don't know all the details of the top of my head but basically you need to use appcmd to configure and enable the net.msmq binding activation.

Check this blogpost or this screencast should give you all the details.

Related Solutions

Wcf – Using Windows Services to process MSMQ messages via WCF

Q1: you can automatically pick up messages from MSMQ, you will need to look into the netmsmqbinding, there are some design considerations that you have to think about though, if you are used to the native MSMQ, you know that you have the ability to peek at the messages. But when you use WCF, you loose that ability to peek. WCF will intercept the messages in MSMQ and you are responsible for keeping your WCF service and the peeking app in synch. You will also need to look into whether you need transactional or non-transactional queues and you will have to modify your binding based on that.

Q2: You will need to host the WCF service in windows service or in IIS7. if you host in IIS7 look into enabling MSMQ WAS listener

Here is a nice article: http://blogs.msdn.com/tomholl/archive/2008/07/12/msmq-wcf-and-iis-getting-them-to-play-nice-part-1.aspx

.net – WCF – How toncrease Message Size Quota

You'll want something like this to increase the message size quotas, in the App.config or Web.config file:

<bindings>
    <basicHttpBinding>
        <binding name="basicHttp" allowCookies="true"
                 maxReceivedMessageSize="20000000" 
                 maxBufferSize="20000000"
                 maxBufferPoolSize="20000000">
            <readerQuotas maxDepth="32" 
                 maxArrayLength="200000000"
                 maxStringContentLength="200000000"/>
        </binding>
    </basicHttpBinding>
</bindings>

And use the binding name in your endpoint configuration e.g.

...
bindingConfiguration="basicHttp"
...

The justification for the values is simple, they are sufficiently large to accommodate most messages. You can tune that number to fit your needs. The low default value is basically there to prevent DOS type attacks. Making it 20000000 would allow for a distributed DOS attack to be effective, the default size of 64k would require a very large number of clients to overpower most servers these days.

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