By default, all nodes are members of the default cluster group. This default cluster group is used as a template for the creation of new cluster groups.

You can create a cluster group using the cluster:group-create <group-name> command:

karaf@root> cluster:group-create book

Here, we created a new cluster group called book. We can see this new cluster group in the cluster groups' list with the cluster:group-list command:

karaf@root> cluster:group-list

   Group                Members
* [default           ] [vostro.local:5701* ]
  [book              ] []

For now, our book cluster group doesn't have any members.

A node can join a cluster group using the cluster:group-join command:

karaf@root>  cluster:group-join book
   Group                Members
* [default           ] [vostro.local:5701* ]
* [book              ] [vostro.local:5701* ]

The cluster:group-join command takes the following two arguments: