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How to confire Apache to work as proxy (load balancer) for j2ee server?

Answer 1

+1 A:

Assuming you have mod_proxy enabled, add to you're sites-available:

   ProxyRequests Off
   <Location "/sapserver">
        ProxyPass http://192.168.0.1
        ProxyPassReverse http://192.168.0.1
   </Location>

Be careful though as this does expose your internal site to the entire internet.

Mark Roddy 2008-10-13 18:47:56

Doesn't work pretty good. I've experienced issues with image rendering and styles of page (j2ee application). Page rendered without graphics and css styles. What I can you advise?

Vik Gamov 2008-10-13 18:54:41

Can you check that the J2EE app isn't referencing the images and CSS via absolute URLs instead of relative?

Mark Roddy 2008-10-14 17:34:39

Answer 2

+1 A:

This is often mistakenly referred to as a reverse proxy. If you use a search engine to find "reverse proxy apache" you will get many good results.

The quick answer is to add something like this to your apache.conf

ProxyPass /sap/ 192.168.0.1/sap/

< Location /sap/ >
    ProxyPassReverse /sap/
< /Location >

See also the modrewrite rools and the [P] option.

jrwren 2008-10-13 18:53:25

Actually, this is a reverse proxy. A forward proxy is a host that channels requests to provide caching and filtering. I don't know why you would say it is "mistakenly" referred to as a reverse proxy.

MattMcKnight 2008-10-14 17:35:28

Answer 3

+2 A:

You mentioned load balancing- so presumably you want to be able to add more Application Servers that are served through a single address. I hope they are stateless or storing session information in a database. You can use Apache to serve as a reverse proxy load balancer with mod_proxy_balancer. Docs are here.

Here's an example of what to add to your httpd.conf from this link.

 <Proxy balancer://myclustername>
  # cluster member 1
  BalancerMember http://192.168.0.1:3000 
  BalancerMember http://192.168.0.1:3001

  # cluster member 2, the fastest machine so double the load
  BalancerMember http://192.168.0.11:3000 loadfactor=2
  BalancerMember http://192.168.0.11:3001 loadfactor=2

  # cluster member 3
  BalancerMember http://192.168.0.12:3000
  BalancerMember http://192.168.0.12:3001

  # cluster member 4
  BalancerMember http://192.168.0.13:3000
  BalancerMember http://192.168.0.13:3001
</Proxy>

<VirtualHost *:80>
  ServerAdmin [email protected]
  ServerName www.meinprof.de
  ServerAlias meinprof.de
  ProxyPass / balancer://meinprofcluster/
  ProxyPassReverse / balancer://meinprofcluster/
  ErrorLog /var/log/www/www.meinprof.de/apache_error_log
  CustomLog /var/log/www/www.meinprof.de/apache_access_log combined
</VirtualHost>

MattMcKnight 2008-10-14 17:39:40

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How to confire Apache to work as proxy (load balancer) for j2ee server?

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