IBM Sysplex

In IBM mainframe computers, a Systems Complex, commonly called a Sysplex, is one or more (up to 32 LPARs) System/390 processors joined into a single unit, sharing the same "Sysplex name" and Couple Data Sets. Put another way, a Sysplex is an instance of a computer system running on one or more physical computers. Sysplexes are often isolated to a single system, but Parallel Sysplex technology allows multiple mainframes to act as one. Sysplexes can be broken down into LPARs, or logical partitions, each running a different operating system.

Components of a Sysplex include:
* A Sysplex Timer which synchronizes all member systems' clocks
* Global Resource Serialization (GRS), which allows multiple systems to access the same resources concurrently, serializing where necessary to ensure exclusive access
* Cross System Coupling Facility (XCF), which allows systems to communicate peer to peer
* Couple Data Sets (CDS)

ee also

* Parallel Sysplex
* LPAR