Disposing WCF with long running [OperationContract(IsOneWay = true)]

Question

I've following service, defined as OneWay, because it's long running (a few minutes) and I can't wait when it finishes (it's used in ASP.NET application).

The problem is that if I call client.Dispose() after the service call, it blocks and after 60s timeout expires with exception.

How should I dispose the client in such scenario? Increasing the timeout of the service isn't solution, because I can't wait so long time with the HTTP request of the web page, where it's used.

[ServiceContract]
public interface IMyService
{        
    [OperationContract(IsOneWay = true)]
    void BeginRun();
}

var client = new MyServiceClient();
client.BeginRun();
client.Close(); //This leads to time-out, how and when to call it?

Thanks for tips.

Answer 1

From your signiture, it seems like you don't need any sort of response. In that case, on the service, when you recieve the BeginRun() call, execute the work on a non-WCF thread. This will free the channel & should allow you to immediately dispose the client.

Even though you've marked the OperationContract as IsOneWay, that doesn't mean WCF immediately releases the channel. A WCF service will not actually return from a one-way call until all of the data has been read from the wire. Depending on your service configuration, this could involve waiting for previous calls to complete (particularly w/ Single concurrency mode sessionful service configurations).

So, for several reasons it's often a good idea to actually execute service work on a separate thread from the WCF thread, which should improve throughput. Take a look at this article on MSDN for additional details.

Answer 2

I would switch your binding to netMsmqBinding. Then from your client your one-way calls will be instantaneous.

Long duration sends over http are problematic at best and complex to manage. Sticking a queue in between will greatly simplify this operation.

Answer 3

You can try the IChannel approach. Or maybe try this, not sure this will work : http://msdn.microsoft.com/en-us/library/ms731177.aspx

Answer 4

You need to add try catch block inside your code and if there is an timeout exception it should abort the client.

        try
        {
            work(client);
            client.Close();
        }

        catch (Exception e)
        {
            client.Abort();
            throw;
        }