If you are doing any work with Oracle Coherence clusters and caches, you MUST download the VisualVM Coherence plugin. It gives a great view of the cluster, members, state, and statistics.
Information and download – https://blogs.oracle.com/oraclecoherence/new:-visualvm-plugin-for-coherence-released-through-the-coherence-incubator
For a full view of the cluster, you will want to connect to the “monitor” JMX instance with the following properties set below. This role has visibility to all members in the cluster.