Setting up Liberty server clusters

A Liberty can be configured into a server cluster for application high availability and scale.

For IBM i platformsDistributed: [AIX MacOS Linux Windows]The collectiveController-1.0 feature and its capabilities are available only in multiple-server products such as WebSphere® Application Server Network Deployment Liberty and WebSphere Application Server for z/OS® Liberty. The feature is not available in single-server products such as WebSphere Application Server Liberty, or WebSphere Application Server Liberty Core. If you have a multiple-server product installation, you can use its collectiveController-1.0 feature to work with collective members from single-server products.

A Liberty server cluster is comprised of two or more Liberty servers configured into a server cluster within a Liberty collective. A Liberty server cluster has a unique name within the collective. The collectiveController-1.0 feature supports several operations on Liberty server clusters through the ClusterManager MBean:
  • List clusters
  • Start cluster
  • Stop cluster
  • List cluster members
  • Generate cluster plug-in configuration

To be part of a server cluster, a Liberty must be a member of a Liberty collective and also be configured with the clusterMember feature.

A collective member can be a member of only one server cluster. All cluster members must be members of the same collective. Multiple server clusters can be configured within the same collective. The following diagram illustrates these relationships.

Figure 1. Liberty server clusters
A collective member can be a member of one and only one server cluster. All cluster members must be members of the same collective.