AsyncController v/s SessionLess Controller

http://weblogs.asp.net/imranbaloch/archive/2011/05/10/asynccontroller-v-s-sessionless-controller.aspx



          AsyncController is introduced in ASP.NET MVC 2 while SessionLess controller is introduced in ASP.NET MVC 3. AsyncController allows you to perform long running I/O operation(s) without making your thread idle(i.e., waiting for I/O operations to complete). On the other hand, SessionLess controller allows you to execute multiple requests simultaneously for single user, which otherwise execute multiple requests sequentially due to session synchronization. Understanding these concepts may be easy for you but I have seen a lot of guys become confused on these concepts. In this article, I will show you how to use AsyncController and SessionLess controller in ASP.NET MVC application. I will also compare them and tell you what to use when, where, and the why.