Request doesn't wait for response in .net

Question

I have a windows service which is uploading files to the other website which is processing them. The problem is that with small files it's working fine and it's getting response from there, but with large files (about 6 minute to process) it leaves forever in a waiting mode.

Here is the part of external website post method code:

try
{
  ...
  LogResults();
  return string.Empty;
}
catch (Exception e)
{
  return e.Message;
}

The problem is that I can see logs even for large files, so it means that website always returning value, but for large files my windows service doesn't wait for them.

And here is the code from windows service

var valuesp = new NameValueCollection
{
     { "AccountId", datafeed.AccountId }
};

byte[] resultp = UploadHelper.UploadFiles(url, uploadFiles, valuesp);
response = Encoding.Default.GetString(resultp);

UploadFiles method returns value for small files, but waiting forever for large ones.

Here is complete code of UploadFiles

public static byte[] UploadFiles(string address, IEnumerable<UploadFile> files, NameValueCollection values)
{
    var request = WebRequest.Create(address);
    request.Timeout = System.Threading.Timeout.Infinite; //3600000; // 60 minutes
    request.Method = "POST";
    var boundary = "---------------------------" +
                   DateTime.Now.Ticks.ToString("x", NumberFormatInfo.InvariantInfo);
    request.ContentType = "multipart/form-data; boundary=" + boundary;
    boundary = "--" + boundary;

    using (var requestStream = request.GetRequestStream())
    {
        // Write the values
        if (values != null)
        {
            foreach (string name in values.Keys)
            {
                var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
                requestStream.Write(buffer, 0, buffer.Length);
                buffer =
                    Encoding.ASCII.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"{1}{1}", name,
                                                          Environment.NewLine));
                requestStream.Write(buffer, 0, buffer.Length);
                buffer = Encoding.UTF8.GetBytes(values[name] + Environment.NewLine);
                requestStream.Write(buffer, 0, buffer.Length);
            }
        }

        // Write the files
        if (files != null)
        {
            foreach (var file in files)
            {
                var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
                requestStream.Write(buffer, 0, buffer.Length);
                buffer =
                    Encoding.UTF8.GetBytes(
                        string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"{2}", file.Name,
                                      file.Filename, Environment.NewLine));
                requestStream.Write(buffer, 0, buffer.Length);
                buffer =
                    Encoding.ASCII.GetBytes(string.Format("Content-Type: {0}{1}{1}", file.ContentType,
                                                          Environment.NewLine));
                requestStream.Write(buffer, 0, buffer.Length);
                requestStream.Write(file.Stream, 0, file.Stream.Length);
                buffer = Encoding.ASCII.GetBytes(Environment.NewLine);
                requestStream.Write(buffer, 0, buffer.Length);
            }
        }

        var boundaryBuffer = Encoding.ASCII.GetBytes(boundary + "--");
        requestStream.Write(boundaryBuffer, 0, boundaryBuffer.Length);
    }

    using (var response = request.GetResponse())
    using (var responseStream = response.GetResponseStream())
    using (var stream = new MemoryStream())
    {
        responseStream.CopyTo(stream);
        return stream.ToArray();
    }
}

What I'm doing wrong here?

EDIT: Locally it's working even for 7-8 minutes processing. But in live environment doesn't. Can it be related with main app IIS settings? Can it be related with windows service server settings?

EDIT 2: Remote server web.config httpRuntime settings

<httpRuntime enableVersionHeader="false" maxRequestLength="300000" executionTimeout="12000" targetFramework="4.5" />

Answer 1

The problem was with Azure Load Balancer, which has Idle Timeout set to 4 minutes by default. The new post of Windows Azure blog says that this timeout is now configurable to the value between 4-30 minutes

http://azure.microsoft.com/blog/2014/08/14/new-configurable-idle-timeout-for-azure-load-balancer/

However, the problem was solved with sending additional KeepAlive bytes via TCP, which told Load Balancer to not kill requests.

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(address);
...
request.Proxy = null;
request.ServicePoint.SetTcpKeepAlive(true, 30000, 5000); //after 30 seconds, each 5 second

Setting Proxy to null (not using proxy) is mandatory action here, because otherwise proxy will not pass tcp bytes to the server.

Answer 2

Upload your files with a method that comply with RFC1867

See this

And then :

 UploadFile[] files = new UploadFile[]
{
new UploadFile(fileName1),
new UploadFile(fileName2)
};

NameValueCollection form = new NameValueCollection();

form["name1"] = "value1";
form["name2"] = "xyzzy";

string response = UploadHelper.Upload(url, files, form);

That's all folks!

EDIT :

I use the method above to upload files with over 100MB in size, I don't use ASP at all, it works just perfect!