When running in a cluster, it is convenient to know where on the cluster specific sessions live (either remotely, or on the local cluster node). Sessions include:
Client sessions, both on the overview and in the detailed view (here, clustering information is already provided)
S2S sessions, both on the overview and in the detailed view
External component sessions, both on the overview and in the detailed view
Chat room occupants
This information should only be displayed when clustering is available, to reduce the noise on systems where the feature is not used.