Disable Session state per-request in ASP.Net MVC

Question

Hi, I am creating an ActionResult in ASP.Net MVC to serve images. With Session state enabled, IIS will only handle one request at a time from the same user. (This is true not just in MVC.)

Therefore, on a page with multiple images calling back to this Action, only one image request can be handled at a time. It's synchronous.

I'd like this image Action to be asynchronous -- I'd like multiple image requests to each execute without needing the previous one to complete. (If the images were just static files, IIS would serve them up this way.)

So, I'd like to disable Session just for calls to that Action, or to specify that certain requests do not have Session state. Anyone know how this is done in MVC? Thanks!

Answer 1

Try serving the images from another domain. So something like images.mysite.com.

This will provide you two benefits: One, sessions are tracked by a cookie, so images.mysite.com won't have the cookie. Two, it will give you an additional two concurrent requests to retrieve images.

Have you considered setting up a HttpHandler to serve up your images?

Answer 2

Rather than implementing an action filter for this, why don't you implement a RouteHandler?

Here's the deal - IRouteHandler has one method - GetHttpHandler. When you make an ASP.Net MVC request to a controller, by default the routing engine handles the request by creating a new instance of MvcRouteHandler, which returns an MvcHandler. MvcHandler is an implementation of IHttpHandler which is marked with the (surprise!) IRequiresSessionState interface. This is why a normal request uses Session.

If you follow my blog post on how to implement a custom RouteHandler (instead of using MvcRouteHandler) for serving up images - you can skip returning a session-tagged IHttpHandler.

This should free IIS from imposing synchronicity on you. It would also likely be more performant because it's skipping all the layers of the MVC code dealing with filters.

Answer 3

On our server, IIS doesn't even know about sessions - it's the ASP.NET stack that handles one request per session at a time. Static files, like images, are never affected.

Is it possible that your ASP.NET app is serving the files instead of IIS?

Answer 4

Change DefaultCOntrollerFactory to custom ControllerFactory class. Default Controller.TempDataProvider use SessionStateTempDataProvider. you can change it.

1.Set web.config/system.web/sessionState:mode="Off".

2.create DictionaryTempDataProvider class.

  public class DictionaryTempDataProvider : ITempDataProvider
  {
    public IDictionary<string, object> LoadTempData(ControllerContext controllerContext)
    {
      return new Dictionary<string, object>();
    }

    public void SaveTempData(ControllerContext controllerContext, IDictionary<string, object> values)
    {
    }
  }

3.Create DictionaryTempDataControllerFactory

  public class DictionaryTempDataControllerFactory : DefaultControllerFactory
  {
    public override IController CreateController(System.Web.Routing.RequestContext requestContext, string controllerName)
    {
      var controller = base.CreateController(requestContext, controllerName) as Controller;
      if (controller!=null)
        controller.TempDataProvider = new DictionaryTempDataProvider();

      return controller;
    }
  }

4.In global.asax.cs Apprication_Start event set DictionaryTempDataControllerFactory.

protected void Application_Start()
{
  RegisterRoutes(RouteTable.Routes);

  ControllerBuilder.Current.SetControllerFactory(
   new DictionaryTempDataControllerFactory()
  );
}