I'm trying to configure reverse proxy rules in vhost.conf. I have Apache-2.2.8 on Ubuntu-8.04, monitored by Plesk-10.4.4.

What I'm trying to achieve is defining a reverse proxy rule that defers all traffic to -say- http://mydomain/tomcat/ to the Tomcat server running on port 8080. I have mod_rewrite and mod_proxy loaded in Apache. As far as I understand mod_proxy docs, entering following rules in /var/www/vhosts/mydomain/conf/vhost.conf should work:

<Proxy *>
  Order deny,allow
  Allow from all
</Proxy>

ProxyRequests off
RewriteRule ^/tomcat/(.*)$ http://mydomain:8080/$1 [P]

Yet, I am getting a HTTP 500: internal server error when requesting above URL. (Note: I decided to use a rewrite rule in order to at least get some information logged.)

I have made mod_rewrite log extensively, and find following entries in the logs [note: due to a limitation of max. 2 URLs in posts of new users, I have modified all following URLs so that they only contain 1 slash after http:. In case you're suspecting typos: this was done on purpose):

81.241.230.23 - - [19/Mar/2012:16:42:59 +0100] [mydomain/sid#b06ab8][rid#1024af8/initial] (2) init rewrite engine with requested uri /tomcat/testApp/

81.241.230.23 - - [19/Mar/2012:16:42:59 +0100] [mydomain/sid#b06ab8][rid#1024af8/initial] (3) applying pattern '^/tomcat/(.*)$' to uri '/tomcat/testApp/'

81.241.230.23 - - [19/Mar/2012:16:42:59 +0100] [mydomain/sid#b06ab8][rid#1024af8/initial] (2) rewrite '/tomcat/testApp/' -> 'http:/mydomain:8080/testApp/'

81.241.230.23 - - [19/Mar/2012:16:42:59 +0100] [mydomain/sid#b06ab8][rid#1024af8/initial] (2) forcing proxy-throughput with http:/mydomain:8080/testApp/

81.241.230.23 - - [19/Mar/2012:16:42:59 +0100] [mydomain/sid#b06ab8][rid#1024af8/initial] (1) go-ahead with proxy request proxy:http:/mydomain:8080/testApp/ [OK]

This suggests that the rewrite and proxy part is processed ok; still the proxied request produces a 500 error. Yet:

• Addressing the testApp directly via http:/mydomain:8080/testApp does work.
• The same setup does work on my local computer.

Is there something else (Plesk-related, perhaps?) I should configure?

Many thanks for any pointers!

Ron