IIS 7.0 Managed pipeline Mode

If you have configured any application on IIS 6 or IIS 7 you might have configured application pools as well. One of the new things added on IIS 7 which makes it much different for ASP.NET application is managed pipeline mode. I had never observed it till these days and was not aware of the difference. If you are hosting your ASP.Net application on IIS 7 setting this feature appropriately would give you lot of boost on your application performance.

In above image you can see Integrated and Classic as Managed Pipleline Mode. What exactly the difference between these two and how these two works? Here are few things I found on my search


Classic mode:

When the application pool is made as classic, it works exactly like IIS 6.0. ASP.NET requests first go through native processing steps in IIS and are then routed to Aspnet_isapi.dll for processing of managed code in the managed runtime. Finally, the request is routed back through IIS to send the response. This separation of IIS and ASP.Net request processing results in duplication of some processing steps like authentication and authorization. Here are the steps that IIS will follow on classic mode

• IIS core received the incoming HTTP request
• The request is processed through ISAPI.
• The request is passed to ASP.NET.
• The request passes back through ISAPI.
• The request passes back through the IIS core -> HTTP response delivered

Integrated mode:

The request-processing models of IIS and ASP.NET are integrated into a unified process model. This model eliminates steps that were previously duplicated in IIS and ASP.NET, such as authentication. Additionally, Integrated mode enables the availability of managed features to all content types

Here are the steps

• The incoming HTTP request is received through the IIS core and ASP.NET.
• The appropriate handler executes the request and delivers the HTTP response