How does rgmanager work?
The rgmanager program is complex. There is a service monitor that checks for services that are defined in the cluster to make sure they’re running. The services may be configured to run on a subset of nodes in the cluster, which I call a service group. A cluster may have many service groups, so even if your cluster has lots of nodes, you can restrict the service to run on only the nodes you want. A cluster may have multiple service groups, so you can have a group of nodes. For example, you can define an NFS service to run on a group of nodes, and an Apache httpd service to run on a different group of nodes. If a service fails, a script is called to automatically restart the service. If a node fails, the service may be relocated to a different node in the service group.
