You configure the software to start or stop services on each node in the cluster in case one or more services fail. For example, if you use an active/passive cluster, you can configure the cluster manager to stop all of the services in the active node and start all of the services in the passive node in case one of the services in the active node fails.

A cluster manager typically consists of the following components:

Main application that manages the entire cluster and sends commands to start, stop, or verify the availability of the services. You can install the application anywhere in the cluster. To improve reliability, install the application outside of the cluster.
Agent that monitors and reports the status of the services in each node to the main application. The agent can start or stop the services with commands from the main application. You install the agent on each node in the cluster and define which services to monitor.