HttpWebRequest times out on second call

Question

Why does the following code Timeout the second (and subsequent) time it is run?

The code hangs at:

using (Stream objStream = request.GetResponse().Ge         


        

Answer 1

On the heels of the previous answers, I wanted to add a couple more things. By default HttpWebRequest allows only 2 connections to the same host (this is HTTP 1.1 "niceness"),

Yes, it can be overriden, no I won't tell you how in this question, you have to ask another one :) I think you ought to look at this post.

I think that you are still not quite disposing of all your resources connected with the HttpWebRequest, so the connection pooling comes into play and that's the problem. I wouldn't try to fight the 2 connections per server rule, unless you really have to.

As one of the posters above noted, Fiddler is doing you a bit of a disservice in this case.

I'd add a nice finally {} clause after your catch and make sure that as the above post notes, all streams are flushed, closed and references to the request object are set to null.

Please let us know if this helps.

Answer 2

I had the same issue, and I resolved it ensuring I call the Abort() method on each of the request object created.

Answer 3

I read the post tagged as answer above and it didn't really work for me above. I ended up rewriting the code using the using tags and added a CloseConnectionGroup segment someone else recommended here. Ultimately this is what the code looks like:

System.Net.HttpWebRequest webRequest = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(imageUrl);
                webRequest.AllowWriteStreamBuffering = true;
                webRequest.Timeout = 30000;
                webRequest.ServicePoint.ConnectionLeaseTimeout = 5000;
                webRequest.ServicePoint.MaxIdleTime = 5000;

                using (System.Net.WebResponse webResponse = webRequest.GetResponse())
                {

                    using (System.IO.Stream stream = webResponse.GetResponseStream())
                    {
                        image = System.Drawing.Image.FromStream(stream);
                    }
                }

                webRequest.ServicePoint.CloseConnectionGroup(webRequest.ConnectionGroupName);
                webRequest = null; 
            }

Answer 4

By any chance were you using a test app with the default name of WindowsFormsAppN? I had the same problem that I spent a week debugging because it worked in my production code but not in a simple test solution I was building. In the end, I determined this behavior was unique to using the default solution name instead of a properly named solution.

Edit: I discovered my issue was related to using BitDefender as my AV software. The WindowsFormsAppN programs were all blocked.

Answer 5

ran into the same problem with timeouts on subsequent requests to the server despite disposing/flushing/closing everything properly. try flushing your connection group, worked for me:

myRequest.ServicePoint.CloseConnectionGroup(myRequest.ConnectionGroupName);

also, ensure you're not inadvertently creating other HttpWebRequest/Request objects elsewhere in your application that aren't being properly terminated/disposed, as this will increase the numbers of connections in the Service Point.

Answer 6

I've set http time out to 10 minutes and it worked for me.

Setting to timeout=infinite was taking more time and my program was going in hung mode.