The Cluster Manager is responsible for node and cluster management. Every node within a Couchbase cluster includes the Cluster Manager component.
The Cluster Manager is responsible for the following within a cluster:
Statistics gathering and aggregation
Security for administrative and client access
Client proxy service to redirect requests
Access to the Cluster Manager is provided through the administration interface on a dedicated network port and through dedicated network ports for client access. Additional ports are configured for inter-node communication.