To configure PAS for OpenEdge to enable Tomcat load balancing:

  1. Create an instance (lb) that is dedicated to load balancing.

    You can use the PASMAN create action to instantiate an instance. The instance must be named either lb or jklb. No other configuration is required, but note that you should not deploy any web applications to the lb instance.

  2. (Optional) Create an instance (status) to gather metrics about the instances in the load balancing group.

    You can use the PASMAN create action to instantiate an instance. The instance must be named status or jkstatus. No other configuration is required, but note that you should not deploy any web applications to the status instance.

    Also note that the lb automatically keeps track of the run-time status of instances in its load balancing group. It will not forward a request to an instance that crashed or is not running. Therefore, the status instance is only required if you want to monitor performance data about the instances in the load balancing group.

  3. Generate and deploy a worker.properties file.

    The worker.properties file is a Tomcat feature that defines the load balancing instance (lb), the status instance (status), and the instances that handle requests.

    You can create a preliminary worker.properties file using the PASMAN workers action. The action gathers information about all instances registered to the local PAS for OpenEdge core server (CATALINA_HOME).
    Note: There must be an instance named lb or jklb that will function as the load balancer.
    The workers action only includes local instances. If you have instances on multiple machines, then you must:
    1. Run the PASMAN workers action on each instance.
    2. Combine the workers.properties file from each machine into a single workers.properties file.
    3. Comment out the workers.common.host property.
    4. Add a workers.instance_name.host=host_name property to each instance.
    Note:
    • The PASMAN workers action references the content of the $CATALINA_HOME/extras/workers.template file when it builds a preliminary worker.properties file. You can modify the workers.template file to include settings that are typical in your local configuration.
    • The preliminary worker.properties is created in the temp directory of the CATALINA_HOME server (for example, $DLC/servers/pasoe/temp). Use this file as a starting point; you may need to modify parameter values to better suit your particular application configuration.