Key concepts

master pool
A Control Center resource pool that contains only the Control Center master host. By isolating the master host in its own pool and configuring a ZooKeeper ensemble, Zenoss Core services are not affected when Control Center internal services are temporarily unavailable. The recommended name for this pool is master.
Zenoss Core pool
A Control Center resource pool that runs Zenoss Core infrastructure services and other key services. This resource pool must be on the same subnet as the master pool. A Zenoss Core pool includes a minimum of two Control Center hosts. The recommended name is Zenoss Core.