Nodes

Nodes form the core of an HACMP™ cluster. A node is a processor that runs both AIX® and HACMP. HACMP supports pSeries uniprocessor and symmetric multiprocessor (SMP) systems, and the Scalable POWERParallel processor (SP) systems as cluster nodes. The HACMP, an SMP system looks just like a uniprocessor. SMP systems provide a cost-effective way to increase cluster throughput. Each node in the cluster can be a large SMP machine, extending an HACMP cluster beyond the limits of a single system and allowing thousands of clients to connect to a single database.

In an HACMP Cluster, up to 32 computers or nodes cooperate to provide a set of services or resources to other remote clients. Clustering these servers to back up critical applications is a cost-effective high availability option. A business can use more of its computing power, to ensure that its critical applications resume running after a short interruption caused by a hardware or software failure.

In an HACMP cluster, each node is identified by a unique name. A node might own a set of resources (disks, volume groups, filesystems, networks, network addresses, and applications). Typically, a node runs a server or a “back-end” application that accesses data on the shared external disks.

HACMP supports from 2 to 32 nodes in a cluster, depending on the disk technology used for the shared external disks. A node in an HACMP cluster has several layers of software components.