WebRequest/WebResponse Memory leak

Question

I have an .Net Framework #4.0 application that makes a large number of web requests using the WebRequest/WebResponse classes , as i see it has memory leak (or maybe i am doing something wrong) I Wrote some small simple application that demonstrates this:

class Program
{

    public static void Main(string[] args)
    {
        while(true)
        {
            var webRequest = (HttpWebRequest)WebRequest.Create("http://www.gooogle.com");
            Init(webRequest);
            using (var webResponse = (HttpWebResponse)webRequest.GetResponse())
            {
                var responseStream = webResponse.GetResponseStream();

                responseStream.ReadTimeout = 30;
                var streamReader = new StreamReader(responseStream, Encoding.UTF8);
                var page = streamReader.ReadToEnd();

                streamReader.Close();
                streamReader.Dispose();

                responseStream.Close();
                responseStream.Dispose();

                webResponse.Close();

                Console.WriteLine("Done");

                //GC.Collect();
            }
        }
    }

     private static void Init (HttpWebRequest webRequest)
     {
         webRequest.Method = "GET";
         webRequest.Host = "www.gooogle.com";
         webRequest.UserAgent =
             "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; GTB6.5; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; OfficeLiveConnector.1.4; OfficeLivePatch.1.3; .NET4.0C; .NET4.0E; InfoPath.3) chromeframe/5.0.375.62";
         webRequest.Accept =
             "application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";
         webRequest.KeepAlive = true;
     }
}

The only one solution i came up with is use GC.Collect() (unmarked in example) , All the object are disposed , all streams are closed , am I missing something ?

I found something but i don't understand the reason , if i minimize Console the memory usage decreases and looks O.K , what can be the reason for that is there a problem with Conosole or WinForm , how can i fix it ?

Answer 1

Have a look at this (source):

Symptoms

When you use the HttpWebRequest class to send lots of data for a HTTP POST or PUT request, the request may fail on a computer that is running the Microsoft .NET Framework. Additionally, you may receive an out-of-memory exception.

You may notice that the application that uses the HttpWebRequest class consumes lots of memory. When you use Performance Monitor to monitor the application that uses the HttpWebRequest class, the Private Bytes count will continue to increase as data is sent.

Cause

This issue occurs because the .NET Framework buffers the outgoing data by default when you use the HttpWebRequest class. KB article http://support.microsoft.com/kb/908573 documents the original issue.

Resolution

To work around this issue, set the HttpWebRequest.AllowWriteStreamBuffering property to false. By doing this, outgoing data (entity body) for the POST or the PUT request will not be buffered in memory.

In versions of Microsoft .NET Framework earlier than 4.5, setting HttpWebRequest.AllowWriteStreamBuffering property to false would sometimes result in errors when uploading data to authenticated endpoints. For example, you might encounter a System.Net.WebException with the message "This request requires buffering data to succeed". However on deeper investigation the response associated with the exception actually indicates a status code of System.Net.HttpStatusCode.Unauthorized (401). KB article http://support.microsoft.com/kb/908573 documents a workaround of pre-authentication and KeepAlive connection to handle 401 response.

Unlike Microsoft .NET Framework 1.1, 2.0, 3.0, 3.5 and 4.0, Microsoft .NET Framework 4.5 adds new design functionality for the HttpWebRequest.AllowWriteStreamBuffering property. The new functionality can handle the authentication scenario directly as long as the Expect100Continue feature is enabled. The default ServicePointManager.Expect100Continue value is true.