A dynamic cluster is a server cluster that uses weights to balance the workloads of its cluster members dynamically, based on performance information that is collected from the cluster members.
A dynamic cluster is an application deployment target that can expand and contract depending on the workload in your environment. Dynamic clusters work with autonomic managers, including the application placement controller and the dynamic workload manager to maximize the use of your computing resources. Dynamic clusters are required for many of the WebSphere® Extended Deployment autonomic functions, including high availability and service policies.
Dynamic clusters are similar to the server clusters that you can create with WebSphere Application Server Network Deployment, but key differences exist that make dynamic clusters much more powerful.
In all WebSphere Extended Deployment Version 6.0 releases, dynamic clusters are tightly coupled with node groups. Node groups are collections of WebSphere Application Server nodes that defines a boundary for server cluster formation. When you create a dynamic cluster, you select a node group from which to base your dynamic cluster. Depending on the settings that you select for your dynamic cluster, cluster instances are created on the nodes in the node group. Each node group can contain one or more dynamic clusters. The computing power of the node group is divided autonomically among the dynamic clusters, according to the defined business goals.
Server templates are a copy of a server configuration that can be used as a starting point when a server is added to the dynamic cluster. Predefined templates exist for different versions of WebSphere Extended Deployment.