A cluster is a collection of application server instances that can distribute processing among clustered application instances. This provides optimal performance and scalability, along with high availability and failover capabilities for reliability. Implementing JBI applications in a clustered environment ensures continuous processing even when there is a hardware or software failure.
The instances in a cluster share the same set of Java CAPS JBI applications, resources, and configuration information, and can be implemented on one server or can extend over multiple servers. A clustered instance belongs to only one cluster, through there can be multiple clusters on a domain. All settings for a cluster are defined in a single configuration file named cluster_name-config.
In a cluster configuration for JBI components, each component is added to a GlassFish cluster and any Service Assemblies (SA) are deployed to the cluster. Adding a component to a cluster adds the component to all instances of the cluster. Similarly, deploying an SA to a cluster deploys it to all the cluster instances.