Purpose of aspnet_isapi.dll hosted in w3wp - IIS 6 ?

Question

What is the purpose of the ASP.NET ISAPI extension aspnet_isapi.dll that is hosted in the worker process w3wp.exe in IIS 6.0 ?

In IIS 5.0, I understood that this ISAPI extension was responsible for handling all asp.net requests (aspx etc). It was loaded in the IIS process and was responsible for sending the requests to the ASP.NET worker process aspnet_wp.exe using named pipes.

With IIS 6.0, the requests reach w3wp.exe directly from the kernel and the ISAPI extension is later loaded in this worker process.

In the MSDN article (IIS 6.0) here is says *Aspnet_isapi.dll - Queues requests for processing by the managed code ASP.NET engine and performs health monitoring.*

This confuses me.

• Aren't the requests already queues @ the kernel level ?

• Isn't aspnet_isapi.dll unmanged code ? i.e. a regular win32 dll ? And isn't w3wp managed code ?

I am totally lost :-|

Any help would be appreciated !

I have moved this question to Server Fault. Can someone please close this one ? Thanks !

Answer 1

w3wp.exe is not managed code. It is the general-purpose worker process for IIS, and it is written in C.

aspnet_isapi.dll is the thing that provides the ASPNET capability to a w3wp.exe.

It is partly managed and partly unmanaged code. It loads the ASPNET runtime.

None of this is really relevant to the job of programming an ASPNET app.

If you have more questions you might wanna go to serverfault.com