GetRequestStream() is throwing time out exception when posting data to HTTPS url

Try this:

    WebRequest req = WebRequest.Create("https://server-url-xxxx.com");
    req.Method = "POST";
    string json_value = jsonSerializer.Serialize(data); //Body data
    ServicePointManager.Expect100Continue = false;
    using (var streamWriter = new StreamWriter(req.GetRequestStream()))
    {
        streamWriter.Write(json_value);
        streamWriter.Flush();
        streamWriter.Close();
    }
    HttpWebResponse resp = req.GetResponse() as HttpWebResponse;
    Stream GETResponseStream = resp.GetResponseStream();
    StreamReader sr = new StreamReader(GETResponseStream);
    var response = sr.ReadToEnd(); //Response
    resp.Close(); //Close response
    sr.Close(); //Close StreamReader

And review the URI:

• Reserved characters. Send reserved characters by the URI can bring problems ! * ' ( ) ; : @ & = + $ , / ? # [ ]

• URI Length: You should not exceed 2000 characters

I ran into this, too. I wanted to simulate hundreds of users with a Console app. When simulating only one user, everything was fine. But with more users came the Timeout exception all the time.

Timeout occurs because by default the ConnectionLimit=2 to a ServicePoint (aka website). Very good article to read: https://venkateshnarayanan.wordpress.com/2013/04/17/httpwebrequest-reuse-of-tcp-connections/

What you can do is:

1) make more ConnectionGroups within a servicePoint, because ConnectionLimit is per ConnectionGroups.

2) or you just simply increase the connection limit.

See my solution:

private HttpWebRequest CreateHttpWebRequest<U>(string userSessionID, string method, string fullUrl, U uploadData)
{
    HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(fullUrl);
    req.Method = method; // GET PUT POST DELETE
    req.ConnectionGroupName = userSessionID;  // We make separate connection-groups for each user session. Within a group connections can be reused.
    req.ServicePoint.ConnectionLimit = 10;    // The default value of 2 within a ConnectionGroup caused me always a "Timeout exception" because a user's 1-3 concurrent WebRequests within a second.
    req.ServicePoint.MaxIdleTime = 5 * 1000;  // (5 sec) default was 100000 (100 sec).  Max idle time for a connection within a ConnectionGroup for reuse before closing
    Log("Statistics: The sum of connections of all connectiongroups within the ServicePoint: " + req.ServicePoint.CurrentConnections; // just for statistics

    if (uploadData != null)
    {
        req.ContentType = "application/json";
        SerializeToJson(uploadData, req.GetRequestStream());
    }
    return req;
}

/// <summary>Serializes and writes obj to the requestStream and closes the stream. Uses JSON serialization from System.Runtime.Serialization.</summary>        
public void SerializeToJson(object obj, Stream requestStream)
{
    DataContractJsonSerializer json = new DataContractJsonSerializer(obj.GetType());
    json.WriteObject(requestStream, obj);            
    requestStream.Close();
}

I don't know if this will help you with your specific problem but you should consider Disposing some of those objects when you are finished with them. I was doing something like this recently and wrapping stuff up in using statements seems to clean up a bunch of timeout exceptions for me.

            using (var reqStream = request.GetRequestStream())
            {
                if (reqStream == null)
                {
                    return;
                }

              //do whatever

            }

also check these things

• Is the server serving https in your local dev environment?
• Have you set up your bindings *.443 (https) properly?
• Do you need to set credentials on the request?
• Is it your application pool account accessing the https resources or is it your account being passed through?

• Have you thought about using WebClient instead?

  using (WebClient client = new WebClient())
      {               
          using (Stream stream = client.OpenRead("https://server-url-xxxx.com"))
          using (StreamReader reader = new StreamReader(stream))
          {
              MessageBox.Show(reader.ReadToEnd());
          }
      }
  

EDIT:

make a request from console.

internal class Program
{
    private static void Main(string[] args)
    {
        new Program().Run();
        Console.ReadLine();
    }

    public void Run()
    {

       var request = (HttpWebRequest)System.Net.WebRequest.Create("https://server-url-xxxx.com");
        request.Method = "POST";
        request.ProtocolVersion = System.Net.HttpVersion.Version10;
        request.ContentType = "application/x-www-form-urlencoded";

        using (var reqStream = request.GetRequestStream())
        {
            using(var response = new StreamReader(reqStream )
            {
              Console.WriteLine(response.ReadToEnd());
            }
        }
    }
}

I ran into the same issue. It seems like it is solved for me. I went through all my code making sure to invoke webResponse.Close() and/or responseStream.Close() for all my HttpWebResponse objects. The documentation indicates that you can close the stream or the HttpWebResponse object. Calling both is not harmful, so I did. Not closing the responses may cause the application to run out of connections for reuse, and this seems to affect the HttpWebRequest.GetRequestStream as far as I can observe in my code.