The forerunner to Parallel Sysplex was Virtual Coupling, a technique which allowed up to 12 IBM 390 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:
The Coupling Facility may be either a dedicated external system (a small mainframe, such as a System z9 BC, specially configured with only coupling facility processors) or integral processors on the mainframes themselves configured as ICFs (Internal Coupling Facilities). Both are popular — there are minor technical advantages and disadvantages between external CF and ICF installations. For achieving highest availability without unnecessary spending, IBM generally recommends combining a single external CF with an ICF. However, with z/OS 1.8 and higher an ICF-only implementation is quite viable.
A Parallel Sysplex has at least two CFs or ICFs for redundancy (or at least one of each). Every mainframe participating in a Parallel Sysplex does not need an ICF or its own external CF — mainframes merely attach, via cables, to the external CFs or ICFs.
Server Time Protocol (STP) replaced the Sysplex Timers beginning in 2005 for newer mainframe models. While the Sysplex Timers are physically separate machines, STP is an integral feature within the mainframe itself. With STP and ICFs it is now possible (and common) to construct a complete Parallel Sysplex installation solely with two mainframes and cabling. Moreover, a single mainframe can contain the internal equivalent of a complete physical Parallel Sysplex, so there is no technical requirement to have a multi-frame Parallel Sysplex at least for application testing and development purposes.
Parallel Sysplex enables another major capability: online maintenance. For example, with Parallel Sysplex it is possible (and common) to configure DB2 for z/OS to deliver continuous business service, permitting whole version upgrades and patches while DB2 continues to run and serve users.
US Patent Issued to International Business Machines on Jan. 29 for "Horizontal Scaling of Stream Processing" (Texas Inventors)
Jan 31, 2013; ALEXANDRIA, Va., Jan. 31 -- United States Patent no. 8,365,172, issued on Jan. 29, was assigned to International Business...