2.1.1 Clustering
A cluster is a set of application servers that are managed together and participate in workload management. Application servers participating in a cluster can be on the same node, or on different nodes. A Network Deployment cell can contain no clusters or it can have many clusters, depending on the need of the administration of the cell. The cluster is a logical representation of the application servers. It is not necessarily associated with any node, and does not correspond to any real server process running on any node. A cluster contains only application servers, as well as the weighted workload capacity associated with those servers.