JES3plus

What is the Job Entry Subsystem (JES)

The Job Entry Subsystem (JES) is a component of IBM’s z/OS operating system responsible for managing batch workloads. Minimum JES functionality includes reading jobs into the system, selecting them for processing, managing/printing their output, and purging them from the system. Uniquely, JES3 provided multisystem coupling, intelligent tape sharing, resource routing, load balancing, dynamic initiators, pre-execution device setup, job networks, deadline scheduling, multisystem consoles, a JESplex-wide merged log, and other capabilities that simplified the operation and management of loosely-coupled systems nearly two decades before the emergence of sysplex support in the base operating system. Most of these unique JES3 functions continue to have relevance even today.

JES3plus is a plug-compatible solution for IBM JES3 customers not wishing to embark on a costly and potentially risky JES2 conversion. This means:

User exits, source modifications (if any), and message automation continue to work unchanged

Operator commands are unchanged

Job and device setup are fully supported and continue to work unchanged

Tape high-watermark setup is fully supported and continues to work unchanged

NJE and RJP partner interactions with your systems are unchanged

DevTest and production JCL continue to work unchanged

Production control procedures continue to work unchanged

Log and output post-processing scripts continue to work unchanged

JES3’s often superior performance characteristics are unchanged

Enhancements released:

I/O performance improvement (ACKD support)

I/O performance improvement (zHPF support)