Abstract: A shared-disk cluster system includes a cluster membership manager framework which coordinates the joining or leaving among all nodes in a cluster including taking the multiple layers of involved subsystems through transitions. Subsystems are notified of transitions in particular order depending upon the transition, and all nodes' subsystems receiving a notification must process that notification prior to another layer of subsystems being notified. One of the subsystems registered for notification is an event manager in user space. The event manager carries out transfers of client services, including user applications, resulting from nodes joining and leaving the cluster. This includes a registration and launch service which registers a node, or multiple nodes, in a cluster which claims, or is assigned, responsibility for the service and provides an optional launching function which initiates the client service upon successful registration.