WCF server-side timeout

Question

Is there a way to tell a WCF service to response to a request (with or without aborting it's processing) after a certain amount of time, even if it didn't finish yet, something like a server-side timeout policy?

Answer 1

I suppose you could do this by starting a new Thread as soon as the WCF operation starts. The real work then happens on the new thread and the original WCF request thread waits using a Thread.Join() with a specific timeout. If the timeout occurs the worker thread can be canceled using a Thread.Abort().

Something like this:

public string GetData(int value)
{
    string result = "";
    var worker = new Thread((state) =>
    {
        // Simulate l0ng running
        Thread.Sleep(TimeSpan.FromSeconds(value));
        result = string.Format("You entered: {0}", value);
    });

    worker.Start();

    if (!worker.Join(TimeSpan.FromSeconds(5)))
    {
        worker.Abort();
        throw new FaultException("Work took to long.");
    }

    return result;
}

Answer 2

I don't know why you want to do this - you should probably edit your question to say what you're trying to accomplish.

If I had to do this, then I would have the web service pass the request off to a separate Windows Service, possibly by using WCF over MSMQ. I would have a timeout on that request. If the request didn't finish in time, I'd simply return a Timeout fault. The actual request would not be impacted.

Answer 3

Implement your service using the asynchronous model and have some code monitoring your outstanding requests to see if they've taken too long.

Then, if a timeout occurs before the request can be answered in the real way, then call their callback. The WCF stack provides this when it calls your

BeginFoo( fooParam1, fooParam2, AsyncCallback callback, object state)

Then throw or return your fault/timeout exception or response in the correponding EndFoo() method.

Make sure to not call their callback again if the real answer comes along eventually.

It'll take some getting used to asynchronous wcf programming, but no, apparently there is no server side setting.

Also, you should try to use a client that supports timeout or cancellable requests because you might not be able to rely on the server to time out the request for you. There might not be connectivity or the server machine might have another problem.

Cheers, Chris