Override proxy decision with parameter

[pavel.orehov]

Hi,

Our setup is HTTPD with Tomcat(s) and mod_cluster between them via AJP.

We are not using sticky session, so every request may be proxied to different Tomcat instance.

My question is if there is a way to proxy a request to specific Tomcat instance by for example URL parameter ?

For example, assume the following setup:

- Tomcat 1 with context /test

- Tomcat 2 with context /test

Request https://host:8443/test?node=1 will be proxied to Tomcat 1

Request https://host:8443/test?node=2 will be proxied to Tomcat 2

Thanks,

Pavel

[jfclere]

Use mod_rewrite for that.

[pavel.orehov]

If I understand correctly using mod_rewrite, configuration would have to be updated for any cluster setup change, for example, if /test context moved from Tomcat 2 to Tomcat 3.

Is there is solution with mod_rewrite or any other which would not require configuration changes when a context moved from one Tomcat instance to another ?

And assuming that mod_rewrite is the only solution, will client be still proxied or will be redirected ?

Thanks,

Pavel

[rhusar]

I think I see what you are looking for exactly, but I don't think there is a straightforward way to configure that.

But to turn it the other way, always deploy a the specific context only on one server (you would need to break that from the existing webapp), rewrite existing URL to the new context. In AS5 you could do that by HA singleton deployer.

[jfclere]

A RewriteMap could limit the changes to a file ouside the httpd.conf

[pavel.orehov]

This configuration in httpd.conf works great:

RewriteEngine on

RewriteCond %{QUERY_STRING} ajp-port=(.*)

RewriteRule ^(.*)$ ajp://%{SERVER_ADDR}:%1%{REQUEST_URI} [P,QSA,L]

Then in URL I need to specify AJP port as parameter, e.g.:

https://hostname:8443/myapp?ajp-port=8609

I know the AJP port since I define the port in our cluster management application.