High Availability Cluster Multi-Processing for AIX

The IBM HACMP software provides a low-cost commercial computing environment that ensures quick recovery of mission-critical applications from hardware and software failures.
HACMP has two major components: high availability (HA) and cluster multi-processing
(CMP).
With HACMP software, critical resources remain available. For example, an HACMP cluster could run a database server program that services client applications. The clients send queries to the server program that responds to their requests by accessing a database, stored on a shared
external disk.
This high availability system combines custom software with industry-standard hardware to minimize downtime by quickly restoring services when a system, component, or application fails. Although not instantaneous, the restoration of service is rapid, usually within 30 to 300 seconds.
In an HACMP cluster, to ensure the availability of these applications, the applications are put under HACMP control. HACMP takes measures to ensure that the applications remain available to client processes even if a component in a cluster fails. To ensure availability, in case of a component failure, HACMP moves the application (along with resources that ensure access to the application) to another node in the cluster.