Send multiple WebRequest in Parallel.For

Question

I want to send multiple WebRequest. I used a Parallel.For loop to do that but the loop runs once and the second time it gives error while getting response.

Error:

The operation has timed out

Code :

Parallel.For(0, 10, delegate(int i) {
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create(
 new Uri("http://www.mysite.com/service"));
 string dataToSend = "Data";
 byte[] buffer = System.Text.Encoding.GetEncoding(1252).
 GetBytes(dataToSend);
 request.Method = "POST";
 request.ContentType = "application/x-www-form-urlencoded";
 request.ContentLength = buffer.Length;
 request.Host = "www.mysite.com";
 Stream requestStream = request.GetRequestStream();
 requestStream.Write(buffer, 0, buffer.Length);
 requestStream.Close();
 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
});

• Darin Dimitrov: It gives you an error message? Really? And is there some particular particular question you would like to ask?
• Panagiotis Kanavos: What is the exception, where does it occur? Are you sure the server isn't actually timing out?

Answer 1

Most likely the problem is that you need to call response.Close() after you're done processing the response.

Answer 2

In addition to what Jim Mischel said about calling Close on the response, you also need to factor in that, by default, .NET limits an application to only two active HTTP connections per domain at once. To change this you can set System.Net.ServicePointManager.DefaultConnectionLimit programmatically or set the same thing via config using the <system.net><connectionManagement> configuration section.