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 (see Section 1.2.16, “Administration Tools”) on a dedicated network port , and through dedicated network ports for client access. Additional ports are configured for inter-node communication.