Implementation Guide › Architectural Considerations › Architectural Use Cases › Redundancy and High Availability › Policy Server to Session Store Communication

Policy Server to Session Store Communication

If you deploy a session store, all Policy Servers in the environment must use the same session store database.

Deploying a master session store is a way to achieve session store redundancy. A master session store lets each Policy Server communicate with the closest replicated version. This method of communication:

• Improves the performance of geographically separated Policy Servers. Sending Policy Server requests to a centralized session store outside a certain locale can result in increased network communication overhead and network congestion.
• Allows for failover. If a primary session store fails, Policy Servers failover to a secondary session store.

Note: For more information about configuring replication, see your vendor–specific documentation. For more information about configuring session store failover, see the Policy Server Administration Guide.

The following diagram illustrates all Policy Servers sharing a common view into a session store.