Sun GlassFish Enterprise Server v2.1.1 High Availability Administration Guide

In-Memory Replication on Other Servers in the Cluster

In-memory replication on other servers provides lightweight storage of session state data without the need to obtain a separate database, such as HADB. This type of replication uses memory on other servers for high availability storage of HTTP session and stateful session bean data. Clustered server instances replicate session state in a ring topology. Each backup instance stores the replicated data in memory. Replication of session state data in memory on other servers enables sessions to be distributed.

The use of in-memory replication requires the Group Management Service (GMS) to be enabled. For more information about GMS, see Group Management Service.

If server instances in a cluster are located on different machines, ensure that the following prerequisites are met: