In computing, a Parallel Sysplex is a cluster of IBM mainframes acting together in a single system image, usually with z/OS. A Parallel Sysplex combines data sharing (typically using Peer to Peer Remote Copy) and parallel computing to allow a cluster of up to 32 computers to share a workload for high performance and high availability.
The forerunner of the Parallel Sysplex was Virtual Coupling, a technique which allowed up to 12 IBM 3090 systems to execute jobs in parallel. The true Parallel Sysplex was introduced with then-new mainframe models in April, 1994. IBM continues to improve and enhance Parallel Sysplex.
Major components of a Parallel Sysplex include:
- Coupling Facility (CF) hardware, allowing multiple processors to share, cache, update, and balance data access;
- A Sysplex Timer to synchronize the clocks of all member systems.
IBM will replace the Sysplex Timer with Server Time Protocol starting in late 2005.