Web application crashes after deploying to azure because of WebRequestHandler

Question

I have an API that fetches data from other service. The following code works great on local IIS:

if (model.Phone[0] != '+')
        {
            model.Phone = "+" + model.Phone;
        }

        string data = Newtonsoft.Json.JsonConvert.SerializeObject(new { ID = Guid.NewGuid(), Phone = model.Phone});

        if (!string.IsNullOrEmpty(model.Email))
        {
            data = Newtonsoft.Json.JsonConvert.SerializeObject(new { ID = Guid.NewGuid(), Phone = model.Phone, Email = model.Email });
        }

        logger.Debug("GetDataFromSupplier before try");

        try
        {
            WebRequestHandler handler = new WebRequestHandler();
            X509Certificate2 certificate = GetMyX509Certificate();
            ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
            handler.ClientCertificates.Add(certificate);
            HttpClient client = new HttpClient(handler);
            var content = new StringContent(data, Encoding.UTF8, "application/json");
            var request = client.PostAsync(API_URL, content);
            var result = request.Result;
            return result;
        } catch (Exception ex)
        {
            logger.Debug($"GetDataFromSupplier in catch: {ex.Message}");
            var message = new HttpResponseMessage(HttpStatusCode.BadRequest);
            message.Content = new StringContent(ex.Message);
            return message;
        }

But after i have deployed this code to Azure the session breaks on this line of code:

WebRequestHandler handler = new WebRequestHandler();

The client application gets the 502 HTTP error. I have tried to increase the the RAM of webserver. The catch block not even run. What can cause this problem?

Answer 1

Looking at the documentation for WebRequestHandler https://msdn.microsoft.com/en-us/library/system.net.http.webrequesthandler(v=vs.110).aspx , it may not be the best component to use here.

Perhaps, try the same with HttpClient. https://msdn.microsoft.com/en-us/library/system.net.http.httpclient(v=vs.110).aspx because, WebRequestHandler is more for desktop applications.

Since you mentioned IIS, I am guessing you are not building a desktop app.