How to send http request in asp.net without waiting for a response and without tying up resources

Question

In an ASP.Net application, I need to send some data (urlEncodedUserInput) via http POST to an external server in response to user input, without holding up the page response. It doesn't matter what the response from the other server is, and I don't care if the request fails sometimes. This seems to be operating fine (see below) but I'm concerned that it's tying up resources in the background waiting for a response that will never be used.

Here's the code:

httpRequest = WebRequest.Create(externalServerUrl);

httpRequest.Method = "POST";
httpRequest.ContentType = "application/x-www-form-urlencoded;charset=utf-8";

bytedata = Encoding.UTF8.GetBytes(urlEncodedUserInput);
httpRequest.ContentLength = bytedata.Length;

requestStream = httpRequest.GetRequestStream();
requestStream.Write(bytedata, 0, bytedata.Length);
requestStream.Close();

Pretty standard stuff, but usually at this point you would call httpRequest.getResponse() or httpRequest.beginGetResponse() if you wanted to receive the response asynchronously, but this doesn't seem to be necessary in my scenario.

Am I doing the right thing? Should I call httpRequest.Abort() to clean up or could this prevent the request from being sent on a slow connection?

Answer 1

I think Threadpool.QueueUserWorkItem is what you're looking for. With the addition of lambdas and anonymous types, this can be really simple:

var request = new { url = externalServerUrl, input = urlEncodedUserInput };
ThreadPool.QueueUserWorkItem(
    (data) =>
    {
         httpRequest = WebRequest.Create(data.url);

         httpRequest.Method = "POST";
         httpRequest.ContentType = "application/x-www-form-urlencoded;charset=utf-8";

         bytedata = Encoding.UTF8.GetBytes(data.input);
         httpRequest.ContentLength = bytedata.Length;

         requestStream = httpRequest.GetRequestStream();
         requestStream.Write(bytedata, 0, bytedata.Length);
         requestStream.Close();
         //and so on
     }, request);