ProxyPass Application pool

Topics: Developer Forum, User Forum
Nov 10, 2009 at 7:02 PM


I have two applications running under IIS7 with different app pool on the same web server.

Application1 under apppool1
Application2 under apppool2


Will ProxyPass in v2.0 work  for following case:

link1 needs to be redirected to apppool1
link2 needs to be redirected to apppool2 and
IIRF runs under DefaultAppPool => =>

I know that v1.* doesn't support the above (throws 403.18 error) since if we use rewrite rules we are trying to run IIRF DefaultAppPool and trying to run under different pool (application1 under apppool1)



Nov 11, 2009 at 9:14 AM


First, ProxyPass is not supported in IIRF v1.2, at all.   I think what you are talking about, in v1.2, is that you cannot Rewrite to a target that runs outside the given app pool.   The ProxyPass directive in v2.0 can be used to sort of "work around" that limitation. 

In IIRF v2.0, ProxyPass doesn't really care about the target of the ProxyPass.   The target can be in a different app pool, the same app pool, or a remote box.  If the target is in the same app pool, then I recommend using RewriteRule, in order to save a thread.   But otherwise, no problem. 

But you are also using the word "Redirect" and in that case you may want a RedirectRule., and not ProxyPass.

Good luck.





Nov 13, 2009 at 5:51 PM

Thanks Cheeso.

I was talking about RewriteRule in v1.2.

Its good to hear that ProxyPass in v2 can handle the app pool redirects. The target is in different AppPool. IIRF will run under DefaultAppPool and target in apppool1.

Will there be a huge performance impact with ProxyPass. Please note that ProxyPass will be run on every page request.


Nov 13, 2009 at 7:33 PM

hey ddr,

you wrote: "Its good to hear that ProxyPass in v2 can handle the app pool redirects".  just to clarify, theres no problem with a redirect from one app pool to the other.  The problem is Rewrite.  You cannot rewrite from one app pool to another.  You can always redirect from one app pool to the other.

I haven't done precise performance impact analysis on ProxyPass.  It will incur a performance penalty, but I don't know how much.  when proxying to a different app pool, it has to move the response data through one extra layer of buffers.  This may or may not be significant to you, depending on how much memory is involved (how big the responses are) and what else the machine is doing.

You'd probably wanna test it under load in order to know for sure.  If your server is busy, then you'll want multiple threads requesting stuff concurrently, in order to simulate real-world loads.

good luck!