.net - HttpWebRequest and GetResponse hangs after 1 request; other solutions doesn't work for me

Question

I have set up a connection to Googles C2DM system. It works - sort of.

When I ask C2DM to "ping" my Android device, it does so sometimes, but far from always. The problem shows itself on the server-side of things.

Usually, the first "ping" (after the server has started) goes through. I get a response immediately after I call the webservice and shortly thereafter the "ping" shows up on my Android device.

However, if I shortly after the first "ping" again tell my server to send a "ping", the webservice call fails. It never manages to call the C2DM and after a while I get a WebException (C#) saying the following:

The underlying connection was closed: An unexpected error occurred on a receive.

No other information is there. If I then try to send again, also that call is blocked.

I change nothing in the code, sometimes it manages to call the webservice and sometimes it doesnt. It seems to me there is a "timeout" for calling the Google webservice. If you call it, you need to wait for X seconds before calling again otherwise it just won't return an answer and give the exception. That's just a guess...

Any ideas?

This is the code that executes on send...

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(GoogleMessageUrl); // the google url
request.Method = "POST"
request.KeepAlive = false;

NameValueCollection postFieldNameValue = new NameValueCollection();
postFieldNameValue.Add(RegistrationIdParam, registrationId); // a valid reg id for an android device
postFieldNameValue.Add(CollapseKeyParam, "0");
postFieldNameValue.Add(DelayWhileIdleParam, "0");
postFieldNameValue.Add(DataPayloadParam, message);

string postData = GetPostStringFrom(postFieldNameValue);
byte[] byteArray = Encoding.UTF8.GetBytes(postData);

request.ContentType = "application/x-www-form-urlencoded;charset=UTF-8";
request.ContentLength = byteArray.Length;

request.Headers.Add(HttpRequestHeader.Authorization, "GoogleLogin auth=" + _authTokenString);

Stream dataStream = request.GetRequestStream();
dataStream.Write(byteArray, 0, byteArray.Length);
dataStream.Close();

WebResponse response = request.GetResponse();
HttpStatusCode responseCode = ((HttpWebResponse)response).StatusCode;
if (responseCode.Equals(HttpStatusCode.Unauthorized) || responseCode.Equals(HttpStatusCode.Forbidden))
{
    Console.WriteLine("Unauthorized - need new token");
}
else if (!responseCode.Equals(HttpStatusCode.OK))
{
    Console.WriteLine("Response from web service not OK :");
    Console.WriteLine(((HttpWebResponse)response).StatusDescription);
}

StreamReader reader = new StreamReader(response.GetResponseStream());
string responseLine = reader.ReadLine();
reader.Close();
response.Close();
return responseLine; // it never gets here, but an Exception is caught else where

Updated

I have found out that this is not a C2DM problem, but some problem with HttpWebRequest and its GetResponse, see comments below.

Answer 1

haha, it seems like I have to answer my own question again =)

So, I spent the last 48 hours testing, reading, searching for a solution to the HttpWebRequest problem, or rather the problem with HTTP requests.

All the suggestions I found was of no use to me, except this one:

http://www.eggheadcafe.com/community/vb/14/60113/webclient-to-http-post--error-on-receive.aspx

There is says that

After much research on the internet I stumbled upon suggestions that said to set Keep-Alive to FALSE and to use HTTP1.0.

but he also notes that it didn't work for him:

However, when I try to use that function, I am unable to successfully perform ANY POSTs on EITHER machine - my home or work PC

However, it seems to have solved my issue completely!

Lets hope it sticks =)