Enforcing a strict timeout policy on a server side webrequest

Question

We will need to call out to a 3rd party to retrieve a value using REST, however if we do not receive a response within 10ms, I want to use a default value and continue processing.

I'm leaning towards using an asynchronous WebRequest do to this, but I was wondering if there was a trick to doing it using a synchronous request.

Any advice?

Answer 1

If you are doing a request and waiting on it to return I'd say stay synchronous - there's no reason to do an async request if you're not going to do anything or stay responsive while waiting.

For a sync call:

WebRequest request = WebRequest.Create("http://something.somewhere/url");
WebResponse response = null;
request.Timeout = 10000; // 10 second timeout
try
{
    response = request.GetResponse();
}
catch(WebException e)
{
  if( e.Status == WebExceptionStatus.Timeout)
  {
    //something
  }
}

If doing async:

You will have to call Abort() on the request object - you'll need to check the timeout yourself, there's no built-in way to enforce a hard timeout.

Answer 2

You could encapsulate your call to the 3rd party in a WebService. You could then call this WebService synchronously from your application - the web service reference has a simple timeout property that you can set to 10 seconds or whatever.

Your call to get the 3rd party data from your WebService will throw a WebException after the timeout period has elapsed. You catch it and use a default value instead.

EDIT: Philip's response above is better. RIF.