Sending multiple messages to WCF operation using plinq (multithreading)

Question

I'm not exactly sure how a WCF proxy class will handle sending requests through plinq. Does the following code snippit look ok, or does it look like it could cause problems with shared state across multiple threads? (also, I already understand that a using block is not ideal, this is just an example)

using (var proxy = new ServiceProxyOfSomeSort())
{
    _aBunchOfMessagesToSend.AsParallel()
        .WithDegreeOfParallelism(SomeDegree).ForAll(m =>
    {
        proxy.SomeOperation(m);
    }
}

Should I be creating the proxy once per thread? Is it ok to share the proxy across threads? I don't want to create more proxies than I need to because that is a somewhat expensive operation.

Edit:

I don't really have any of the implementation details of the service on the server side. From a requirements standpoint they should have developed it so that multiple clients could call it at anytime (async). Assuming that they can handle async calls (which may be a big assumption) I'm just trying to figure out if this an acceptable approach from the client side. It is working, I just don't know if there are any gotchas with this approach.

Answer 1

In response to your question about the proxy: you should create a new one per thread. Reusing the proxy tends to work for a while and then throw a fault after tens of requests. As they love to say, its behavior is undefined. The performance overhead of creating new proxies is not huge (after the first one is created), so it shouldn't be a big deal.

As for the discussion of multiple concurrent requests swamping the server: a few, or even a dozen, should be fine - the server can probably handle as many requests as your processor can create threads. Then again, the sudden influx of requests from a single source might be interpreted as a Denial Of Service attack, so you should be wary, particularly if your control over the service is limited.