Question

I have a load tester that calls my WCF service and I’ve built it with options to run the calls in parallel or not. Only when running in parallel, I get the following error for all threads: “The server did not provide a meaningful reply; this might be caused by a contract mismatch, a premature session shutdown or an internal server error.”

This is more or less my code:

            if (runMultiThreaded)
            {
                ParallelOptions options = new ParallelOptions();
                options.MaxDegreeOfParallelism = System.Environment.ProcessorCount;
                ParallelLoopResult loopResult = Parallel.For(0, numberOfTimesToTest, options,
                    (i, loopState) =>
                    {
                        myService.MyOperation();
                        if (loopState.ShouldExitCurrentIteration) return;
                    });
            }
            else
            {
                for (int i = 0; i < test1NumberOfRuns; i++)
                {
                        myService.MyOperation();
                }
            }

Any ideas? Let me know if you need more details.

UPDATE: myService is an instance of my service’s operation contract interface that was created with a ChannelFactory using the CreateChannel method.

Thanks!

Answer 1

I’m assuming your myService is a ClientBase<T> subclass or a channel created explicitly via ChannelFactory<T>::CreateChannel? If so those instances are not guaranteed to be thread safe and you so you need an instance per worker thread.