Operator Monitor Spool Utilization

Spool Full Condition - $S SPL upon warning (Output limits minimize this)

An external message-based automation product can also delete, offload or reroute spool files.

10.3.11 JES2 Testing Techniques

Just as it is important to test new levels of OS/390 in your environment before using them in production, you should also test any JES2 exits or modifications before using them in production.

10.3.11.1 Poly-JES

Secondary JES2 subsystems, or ªPoly-JES,º provide you with the ability to test new releases of JES2, and isolate JES2 work from the primary or production copy of JES2. Many installations find this convenient because it does not require a separate OS/390 test system.

There are two basic configurations for poly-JES:

1.Sharing the spool and checkpoint with the primary JES

2.Dedicating a unique spool and checkpoint to the secondary JES

See ªPoly-JESº in Chapter 1 of theJES2 Initialization and Tuning Guide for detailed guidance. This section is only an addendum to that material. You must use a different character for the CONDEF CONCHAR parameter than the one used by the primary JES, or the secondary JES2 will not initialize.

The number of secondary JES2 subsystems that can be active is limited only by the number of different CONCHAR characters (22).

10.4 POWER/JES2 Detailed Comparisons

The remaining part of this chapter shows detailed comparisons between POWER and JES2 parameters and commands.

10.4.1 Mapping POWER Parameters to JES2 Init Parms

The following tables can help you transfer most of the parameters you have specified for POWER to their equivalent JES2 parameters.

10.4.1.1 Equivalent JES2 Parms for POWER Macro

In general, most of the JES2 initialization parameters have default values so you do not need to specify them. Many installations start with the sample deck in samplib - SHASSAMP - and modify those parameters as necessary.

You should review each of the parameters you specify that is different from the default value using the JES2 Init & Tuning Reference manual. Here is a short table to show you what POWER parameters can be specified in JES2:

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IBM OS/390 10.3.11 JES2 Testing Techniques, POWER/JES2 Detailed Comparisons, Mapping Power Parameters to JES2 Init Parms

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.