The requirements for implementing Apache proxy load balancing are:
1. A properly configured Apache HTTP Server.
You configure a load balancing Apache HTTP Server (commonly referred to as Apache) with a list of available PAS for OpenEdge instances. In addition, you specify whether you want subsequent requests to return to the same instance (session-managed, also known sticky sessions in Apache documentation), or to any available instance (session-free).
If security is an issue, (that is, if you are running Web application available to the public), the recommendation is to install Apache in a DMZ with the PAS for OpenEdge instances running behind a second firewall.
2. Properly configured PAS for OpenEdge instances.
Configuration of instances is contingent on whether sticky sessions are enabled on the Apache load balancer. All the instances must be configured to match the session type of the load balancer.
