ISAPI Filter and the IIS6 Process Model

re: ISAPI Filter and the IIS6 Process Model

Quang Le — Fri, 30 Jun 2006 08:26:06 GMT

excellent article - thank you.

re: ISAPI Filter and the IIS6 Process Model

Valan Joseph — Thu, 07 Sep 2006 08:00:01 GMT

Dave,

What would happen if some one wants to do an URL rewrite? One AppPool may not have an application, but when a URL rewirte causes it to go to another appPool, won't it fail, since it doesn't know the application exists in another appPool.

re: ISAPI Filter and the IIS6 Process Model

Ran Davidovitz — Mon, 30 Mar 2009 10:40:35 GMT

David, i was researching this topic and found your article using Google, Thank you very much for a very good article - saved me some time.

re: ISAPI Filter and the IIS6 Process Model

David.Wang — Mon, 30 Mar 2009 12:00:09 GMT

Valan - yes, URL rewriting across different Application Pools does fail. This happens for both ISAPI Filter and ISAPI Extension who do this.

For compatibility reasons, there is an option to "ignore" this and simply execute the other URL inside of the original AppPool, but as you can see, neither choice is a clean winner.

You either get unexpected 403.19 failures, or you execute code in the wrong Application Pool. Both are not good choices...

//David

re: ISAPI Filter and the IIS6 Process Model

Junaid — Sun, 13 Dec 2009 20:06:47 GMT

David, after changing servers from Win 2003 with IIS6 to Win 2008 with IIS7 we have now encountered the problem you mentioned with url rewriting across different application pools.

How can we get around this? we are faced with 403.18 - Forbidden errors, but our site used to work well before on the previous version of IIS. Please advise, this is urgent.