5.5 Load Balancing OC4J

The Forms Listener Servlet architecture allows you to load balance the system using any of the standard HTTP load balancing techniques available.

The Oracle HTTP Server Listener provides a load balancing mechanism that allows you to run multiple OC4J instances on the same host as the HTTP process, on multiple, different hosts, or on any combination of hosts. The HTTP Listener then routes HTTP requests to the OC4J instances.

The following scenarios are just a few of the possible combinations available and are intended to show you some of the possibilities. The best choice for your site will depend on many factors.

For a complete description of this feature, refer to the OC4J chapter in the Oracle Application Server Performance Guide (available on Oracle Application Server Disk 1 CD or OTN at http://www.oracle.com/technology/products/ias/.

For more Forms-specific information, see the Oracle Developer Suite and Oracle Application Server Release Notes.

The following images illustrate four possible deployment scenarios:

Figure 5-2: Balancing incoming requests between multiple OC4J engines on the same host as the Oracle HTTP Listener.
Figure 5-3: Balancing incoming requests between multiple OC4J engines on a different host to the Oracle HTTP Listener.
Figure 5-4: Balancing incoming requests between multiple OC4J engines on multiple different hosts and multiple different hosts each running an Oracle HTTP Listener.
Figure 5-5: Balancing incoming requests between multiple OC4J engines on a single host but with multiple different hosts each running an Oracle HTTP Listener.

Figure 5-2 Multiple OC4J engines on the same host as the Oracle HTTP Listener

Multiple OC4J instances and HTTP listener on the same host.

Figure 5-3 Multiple OC4J engines on a different host to the Oracle HTTP Listener

Many OC4J instances on different hosts from HTTP listener.

Figure 5-4 Multiple OC4J engines and multiple Oracle HTTP Listeners on different hosts

Many hosted OC4J instances, many hosted HTTP listeners.

Figure 5-5 Multiple Oracle HTTP Listeners on different hosts with multiple OC4J engines on one host

HTTP listeners, different hosts; OC4J instances same host.

For more information about tuning and optimizing Forms Services with the HTTP Listener and OC4J, see Oracle Application Server Performance Guide, available on Oracle Application Server Disk 1 CD or Oracle Technology Network (OTN) at http://www.oracle.com/technology/products/ias/.