Inconsistent behavior from PS to DB Loadbalancing

Document ID : KB000119929
Last Modified Date : 05/11/2018
Show Technical Document Details
Question:
We're running Policy Server with 2 ODBC instances of Session Stores,
when the first instance goes off line, then the connections are going
to the next Session Store, and when the first instance comes back
on-line, the connections doen't goes back to the first instance.

We want to know why ? 
Answer:
At first glance, the behavior is as expected. Even if the nomenclature 
of the configuration suggest there's a loadbalancing, the following 
configuration means failover, and not loadbalancing : 

AlternateServers=(HostName=myserver:PortNumber=1111:ServiceName=myserver.mydomain.com) 
LoadBalancing=1 

How to implement ODBC LoadBalancing for User Store 
https://comm.support.ca.com/kb/how-to-implement-odbc-loadbalancing-for-user-store/kb000016656 

As such, the behavior you see is as expected and by design.