Posted: 11 August 2008 at 3:45am | IP Logged

Hi there,

My organization is currently (still) using isapi_rewrite version 2, together with Tomcat's isapi_redirect, to proxy Tomcat requests using its own proprietary protocol. Servers are Windows 2000.

Isapi_rewrite is installed globally, while isapi_redirect is installed on the site level. Everything works perfectly and no problems since years.

Isapi_redirect works quite similarly to isapi_rewrite, it just needs a list of aliases mapped to specific applications. I always assumed with the above setup that isapi_rewrite has precedence over isapi_redirect.

The problem is: if I try to map on top of the httpd.ini file

Code: RewriteProxy (/.*)? http://[another server IP here]:80$1 [H,I,U]

everything gets redirected EXCEPT the requests supposed to be redirected to Tomcat (=handled by isapi_redirect).
I get the above requests on the original IIS server with entries like:

Code:    GET /<tomcatappname>/<filename>x.isrwhlp

After adding and removing all the isapis and changing their order, my guess is that every alias mapped towards Tomcat do not have a .isrwhlp mapping on IIS.
I tried adding an application with the same name under IIS, but this did not solve the problem.

I wonder if there is a way to overcome this behaviour, or if it is just by design.

Thank you in advance,
h.

Posted: 11 August 2008 at 1:55pm | IP Logged

Hi Lexey,

I probably used the wrong words.

We are using your isapi_rewrite and Apache Tomcat's isapi_redirect.

Every time I try to proxy to another IIS machine, everything gets proxied correctly - except the stuff handled by Tomcat's isapi_redirect.
In this latter case, isapi_rewrite rewrites the request to (sample from source IIS machine's log)
GET /<tomcatappname>/<filename>x.isrwhlp
but this request does not get proxied to the second IIS machine.
Instead, the request is passed over isapi_redirect on the first machine and redirected to Tomcat, that obviously gives a 404.

Note that
1 - isapi_rewrite has precedence over Tomcat's isapi_redirect
2 - there is no double installation of isapi_rewrite

Let me know if I was clearer now :-)

h.

Posted: 12 August 2008 at 4:25pm | IP Logged

Lexey,

Thanks, this works, and guess: I can even use wildcards with latest versions of isapi_redirect :-)

I imagine the explanation is that the request has to arrive to IIS to be handled by the proxy module, so it needed an exclusion for this.

Great job, as usual.

Cheers,
h.