C# – HttpWebRequest times out

chttpwebrequesttimeout

I have read the following 2 articles and have tried implementing the same.

My code is this and the time out occurs here

HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
wr.ContentType = "multipart/form-data; boundary=" + boundary;
wr.Method = "POST";
wr.KeepAlive = false;
wr.CookieContainer = cookieJar;

wr.Proxy = null;
wr.ServicePoint.ConnectionLeaseTimeout = 5000;
Stream rs = wr.GetRequestStream(); // -> Time out error occurs here

My code using that as a sample
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
wr.ContentType = "multipart/form-data; boundary=" + boundary;
wr.Method = "POST";
wr.KeepAlive = false;
wr.CookieContainer = cookieJar;

wr.Timeout = 5000;
wr.Proxy = null;

wr.ServicePoint.ConnectionLeaseTimeout = 5000;
wr.ServicePoint.MaxIdleTime = 5000;

Stream rs = wr.GetRequestStream(); //-->Time out error

Any clues would be helpful. At times I can get 1 request through and all other request fail or everything fails. Am posting to a HTTPS site. No issues when running with Fiddler

UPDATE 1:
I tried following zbugs ideas but that resulted in same issue. the first request goes through the subsequent ones fail. I am closing all response streams as well as calling abort on my request object.

Best Answer

You need to set this.

const int maxIdleTimeout = 5000;
ServicePointManager.MaxServicePointIdleTime = maxIdleTimeout;

If you have more than one client making the request at any given time,

const int maxConnections = 100; //or more/less
ServicePointManager.DefaultConnectionLimit = maxConnections;

http://msdn.microsoft.com/en-us/library/system.net.servicepointmanager.maxservicepointidletime.aspx

Related Solutions

R – Django Authentication from .NET using HttpWebRequest and HttpWebResponse via HTTP POST

Looks ok to me. I recommend using Wireshark to see what your restclient is sending in the headers and and see what your app sending in the headers.

.net – Upload files with HTTPWebrequest (multipart/form-data)

Took the code above and fixed because it throws Internal Server Error 500. There are some problems with \r\n badly positioned and spaces etc. Applied the refactoring with memory stream, writing directly to the request stream. Here is the result:

    public static void HttpUploadFile(string url, string file, string paramName, string contentType, NameValueCollection nvc) {
        log.Debug(string.Format("Uploading {0} to {1}", file, url));
        string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
        byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");

        HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url);
        wr.ContentType = "multipart/form-data; boundary=" + boundary;
        wr.Method = "POST";
        wr.KeepAlive = true;
        wr.Credentials = System.Net.CredentialCache.DefaultCredentials;

        Stream rs = wr.GetRequestStream();

        string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
        foreach (string key in nvc.Keys)
        {
            rs.Write(boundarybytes, 0, boundarybytes.Length);
            string formitem = string.Format(formdataTemplate, key, nvc[key]);
            byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem);
            rs.Write(formitembytes, 0, formitembytes.Length);
        }
        rs.Write(boundarybytes, 0, boundarybytes.Length);

        string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
        string header = string.Format(headerTemplate, paramName, file, contentType);
        byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
        rs.Write(headerbytes, 0, headerbytes.Length);

        FileStream fileStream = new FileStream(file, FileMode.Open, FileAccess.Read);
        byte[] buffer = new byte[4096];
        int bytesRead = 0;
        while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0) {
            rs.Write(buffer, 0, bytesRead);
        }
        fileStream.Close();

        byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
        rs.Write(trailer, 0, trailer.Length);
        rs.Close();

        WebResponse wresp = null;
        try {
            wresp = wr.GetResponse();
            Stream stream2 = wresp.GetResponseStream();
            StreamReader reader2 = new StreamReader(stream2);
            log.Debug(string.Format("File uploaded, server response is: {0}", reader2.ReadToEnd()));
        } catch(Exception ex) {
            log.Error("Error uploading file", ex);
            if(wresp != null) {
                wresp.Close();
                wresp = null;
            }
        } finally {
            wr = null;
        }
    }

and sample usage:

    NameValueCollection nvc = new NameValueCollection();
    nvc.Add("id", "TTR");
    nvc.Add("btn-submit-photo", "Upload");
    HttpUploadFile("http://your.server.com/upload", 
         @"C:\test\test.jpg", "file", "image/jpeg", nvc);

It could be extended to handle multiple files or just call it multiple times for each file. However it suits your needs.

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