Define singleton policies to configure the behavior of singleton deployments or to create singleton MSC services.

A clustered singleton service, also known as a high-availability (HA) singleton, is a service deployed on multiple nodes in a cluster. The service is provided on only one of the nodes. The node running the singleton service is usually called the primary node.

When the primary node either fails or shuts down, another primary is selected from the remaining nodes and the service is restarted on the new primary. Other than a brief interval when one primary has stopped and another has yet to take over, the service is provided by one, but only one, node.