Many people ask how they should implement hardware-based load balancers into an Oracle Access Manager (OAM) implementation. As a rule of thumb: load balancers should be placed in front of the web/application servers where the web gates are installed (i.e., between the browser and the web server) and that is it. OAM has built-in load balance functionality and can manage fail-over on its own. This is referred to as software-based load balancing.
I have seen some environments where clients have put load balancers in between the Identity/Access servers and their directory servers. With OAM this is unnecessary and not advised. According to Oracle documentation,
“performance can be negatively affected by the load balancer, which can terminate a connection but fail to trigger a response that OAM can adjust to. This can cause outages.”
– Performance Tuning 3-39, http://download.oracle.com/docs/cd/E12530_01/oam.1014/e10353.pdf
Hi Brad, Your post was very helpful to me. We had a similar issue when the design was challenged by an Oracle Partner. This specific issues with using load balancers occurs when there is replication involved between the directory server nodes where each nodes use its own store and replicates the data from one node to the other at specified time intervals typically in Sun DS, AD etc. The same does not occur when you are using OID nodes if they use the same data source.
Thanks
Ramesh GK