Any IBM® i implementation of high availability requires a configured cluster to control and manage resilient resources. When used with other data resiliency technologies, such as switched disk, cross-site mirroring, or logical replication, cluster technology provides the key infrastructure that is necessary for high-availability solutions.
Cluster resource services provides a set of integrated services that maintain cluster topology, perform heartbeat monitoring, and allow creation and administration of cluster configuration and cluster resource groups. Cluster resource services also provides reliable messaging functions that keep track of each node in the cluster and ensures that all nodes have consistent information about the state of cluster resources. The IBM PowerHA SystemMirror for i licensed program allows you to configure and manage clusters within your high-availability solution. For additional information on IBM PowerHA SystemMirror for i, see the PowerHA Wiki.
There is also application program interfaces (APIs) and facilities that can be used by application providers or customers to enhance their application availability.
In addition to these IBM technologies, high availability business partners provide applications that use clusters with logical replication technology.