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

Hi, there. I have apache web server installed as frontend and I have j2ee SAP Netweaver Application Server installed in Intranet server. How can I configure apache to forward requests and response to/from j2ee app server. for example, external apache server's ip is 9.20.1.1:80. internal sap server's address is 192.168.0.1/sap/bc/gui/sap/its/webgui?sap_client=200 i wand access to my sap app server for example 9.20.1.1/sapserver/sap/bc/gui/sap/its/webgui?sap_client=200

From stackoverflow

• 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.

  Vik Gamov : 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?

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

• 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.

  MattMcKnight : 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.

• 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 info@meinprof.de
    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>