EclipseLink Solutions Guide for EclipseLink
Release 2.4
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Introduction to the Solution

EclipseLink applications that are deployed to an application server cluster benefit from cluster scalability, load balancing, and failover. These capabilities ensure that EclipseLink applications are highly available and scale as application demand increases. EclipseLink applications are deployed the same way in application server clusters as they are in standalone server environments. However, additional planning and configuration is required to ensure cache consistency in an application server cluster.

EclipseLink uses a shared (L2) object cache that avoids database access for objects and their relationships. The cache is enabled by default and enhances application performance. In an application server cluster, caching can result in consistency issues (such as stale data) because changes made on one server are not reflected on objects cached in other servers. Cache consistency is problematic only for objects that are frequently updated. Read-only objects are not affected by cache consistency. For more details about caching, see:

Various options are available for addressing cache consistency: