Asp.net session never expires when using SignalR and transport mode long polling

Question

We have a web application that uses SignalR for its notification mechanism.The problem is when we are browsing our web application using IE ,SignalR uses Long Polling as its transport type thus sends back requests to our web server therefore Session never expires no matter how long the browser is idle.

We were thinking that maybe we could catch the requests in Global.asax and see if they were from SingalR and set the session timeout to the remaining time (Which I don't think it's a straightforward solution).

Is there any other solution the we are missing ?

Answer 1

The workaround I am currently using is an IHttpModule to check if the request is a Signalr request, if so remove the authentication cookie, this will prevent the ASP.net session timeout from being reset, so if your Session Timeout is 20min and the only requests are Signalr the users session will still timeout and the user will have to login again.

    public class SignalRCookieBypassModule : IHttpModule
    {
        public void Init(HttpApplication application)
        {
            application.PreSendRequestHeaders += OnPreSendRequestHeaders;
        }

        private bool IsSignalrRequest(string path)
        {
            return path.IndexOf("/signalr/", StringComparison.OrdinalIgnoreCase) > -1;
        }

        protected void OnPreSendRequestHeaders(object sender, EventArgs e)
        {
            var httpContext = ((HttpApplication)sender).Context;
            if (IsSignalrRequest(httpContext.Request.Path))
            {
                // Remove auth cooke to avoid sliding expiration renew
                httpContext.Response.Cookies.Remove(DefaultAuthenticationTypes.ApplicationCookie);
            }
        }

        public void Dispose()
        {
        }
    }

I feel this is a real hack solution so would love so other ideas to prevent session timeout renew when data is pushed to the client from the server, or a when javascript client polls an endpoint for data.