Disable Session state per-request in ASP.Net MVC

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!

Solution 1:

If anyone is in the situation I was in, where your image controller actually needs read only access to the session, you can put the SessionState attribute on your controller

[SessionState(SessionStateBehavior.ReadOnly)]

See http://msdn.microsoft.com/en-us/library/system.web.mvc.sessionstateattribute.aspx for more info.

Thanks to https://stackoverflow.com/a/4235006/372926

Solution 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.

Solution 3:

I also came across the same problem and after doing R&D this link worked for me Reference: https://techatfingers.wordpress.com/2016/06/14/session-state-on-action/

1. Create custom Attribute
2. Override the “GetControllerSessionBehavior” method present in class DefaultControllerFactory.
3. Register it in global.aspx

1> Create custom Attribute

public sealed class ActionSessionStateAttribute : Attribute
    {
            public SessionStateBehavior SessionBehavior { get; private set; }          
            public ActionSessionStateAttribute(SessionStateBehavior sessionBehavior)
            {
                SessionBehavior = sessioBehavior;
            }
    }

2. Override

public class SessionControllerFactory : DefaultControllerFactory
{       
        protected override SessionStateBehavior GetControllerSessionBehavior(RequestContext requestContext, Type controllerType)
        {
            if (controllerType == null)
                return SessionStateBehavior.Default;

            var actionName = requestContext.RouteData.Values["action"].ToString();
            Type typeOfRequest=requestContext.HttpContext.Request.RequestType.ToLower() =="get"?typeof(HttpGetAttribute):typeof(HttpPostAttribute);
            // [Line1]
            var cntMethods = controllerType.GetMethods()
                   .Where(m => 
                    m.Name == actionName &&
                    (  (  typeOfRequest == typeof(HttpPostAttribute) && 
                          m.CustomAttributes.Where(a => a.AttributeType == typeOfRequest).Count()>0
                       )
                       ||
                       (  typeOfRequest == typeof(HttpGetAttribute) &&
                          m.CustomAttributes.Where(a => a.AttributeType == typeof(HttpPostAttribute)).Count() == 0
                       )
                    )
                );
            MethodInfo actionMethodInfo = actionMethodInfo = cntMethods != null && cntMethods.Count() == 1 ? cntMethods.ElementAt(0):null;
            if (actionMethodInfo != null)
            {
                var sessionStateAttr = actionMethodInfo.GetCustomAttributes(typeof(ActionSessionStateAttribute), false)
                                    .OfType<ActionSessionStateAttribute>()
                                    .FirstOrDefault();

                if (sessionStateAttr != null)
                {
                    return sessionStateAttr.Behavior;
                }
            }
            return base.GetControllerSessionBehavior(requestContext, controllerType);
 }

3. Register class in Global.asax

public class MvcApplication : System.Web.HttpApplication
 {
        protected void Application_Start()
        {
            // --- other code ---
            ControllerBuilder.Current.SetControllerFactory(typeof(SessionControllerFactory));
        }
}