Distributed session cache overview

The following concepts relate to the distributed session cache, which maintains session state in clustered server environments.

Failover cookies and the distributed session cache are alternate solutions to the same challenge of maintaining session state in clustered server environments. See also Failover solutions.

The distributed session cache replaces the session management server solution that was available in earlier releases of IBM Security Access Manager.

The failover environment
The distributed session cache is most commonly used in a scenario where client requests are directed by a load balancing mechanism to two or more replicated WebSEAL servers.
The distributed session cache
The distributed session cache is an independent service that acts as a centralized session repository for a clustered WebSEAL server environment. Servers in the cluster can use the distributed session cache to provide failover for user sessions.
Failover for the distributed session cache
The distributed session cache server is configured in a clustered environment. You can configure up to four master nodes in the cluster to ensure high availability for the distributed session cache.
Replica sets
A cluster of Security Access Manager servers that use the distributed session cache to share sessions is called a replica set.
Distributed session cache process flow
In a distributed session cache environment, the client browser sends requests to the WebSEAL server cluster, which interacts with the distributed session cache for session management.
Sharing sessions across multiple DNS domains
When operating in a multi-domain environment, you must use a different mechanism to communicate the session identifier to the WebSEAL servers in the different DNS domains.
Advantages of using the distributed session cache to maintain session state
The distributed session cache solution has many advantages over the failover cookies solution for maintaining session state.
Migrating from a Session Management Server (SMS) environment
The distributed session cache replaces the session management server (SMS) solution that was available in earlier releases of IBM Security Access Manager. You can configure IBM Security Access Manager, version 7.0 servers, which previously used the SMS, to use a distributed session cache server in your environment.

Parent topic: Distributed session cache