A node group is a collection of managed nodes. Managed nodes are WebSphere Application Server nodes. A node group defines a boundary for server cluster formation.
Nodes that you organize into a node group need to be similar in terms of installed software, available resources, and configuration to enable servers on those nodes to host the same applications as part of a server cluster. The deployment manager does no validation to guarantee that nodes in a given node group have anything in common.
Node groups are optional and are established at the discretion of the WebSphere Application Server administrator. However, a node must be a member of a node group. Initially, all Application Server nodes are members of the default DefaultNodeGroup node group.
A node can be a member of more than one node group.
On the z/OS platform, an Application Server node must be a member of a sysplex node group. Nodes in the same sysplex must be in the same sysplex node group. A node can be in one sysplex node group only.
Nodes on distributed platforms and i5/OS platforms cannot be members of a node group that contains a node on a z/OS platform. However, nodes on distributed platforms and nodes on i5/OS platforms can be members of the same node group.
To delete a node group, the node group must be empty. The default node group cannot be deleted.
Related tasks
Managing node groups
Creating clusters