CICS data table services

RDO for VSAM files and LSR pools

Some EXEC CICS system programming functions

Autoinstall terminal model manager

Partner resource manager

SAA Communications and Resource Recovery

Some of the file control functions

Recovery manager connectors interfaces.

Domains never communicate directly with each other. Calls between domains are routed through kernel linkage routines. Calls can be made only to official interfaces to the domains, and they must use the correct protocols.

Each domain manages its own data. No domain accesses another domains data directly. If a domain needs data belonging to another domain, it must call that domain, and that domain then passes the data back in the callers parameter area.

Now with the CICS restructuring in mind, here are a few other general system items to consider with your migration:

CICS TS recovery manager facility uses the system log for recovery, thus an intermediate data set, such as the restart data set (DFHRSD) is not required for the CICS TS.

CICS/ESA removed the assembly of a Process Program Table (PPT) and Program Control Table (PCT) from the list of tasks to perform during the migration and installation process of CICS. Now, program processing and program control resource definitions must be defined and reside in the CSD. Therefore, you must have a CSD defined in your CICS/ESA system, with all the associated programs and transaction resources.

The obsolete DFHPCT and DFHPPT macros are not shipped with CICS Transaction Server. However, you are recommended not to migrate the PPT entries to the CSD, but use the new autoinstall facility for programs and MAPS instead.

CICS no longer supports the use of the file control table for VSAM object files, data tables, or shared resource pools. Resource definitions for these VSAM objects can be defined in, and installed from, the CICS system definition (CSD) data set only. CICS/ESA installs only BDAM file definitions from the FCT.

6.1.6CICS Macro Resource Definition Table Changes

Below are commonly identifiable changes required to migrate a CICS/VSE system to CICS TS macro resource definition. These parameters listed below should be viewed as a reminder of items to consider, and not as an inclusive list of parameter changes and/or obsolescence. You should review the CICS Macro Definition, SC33-1648 manual for full details of parameters required for the different macro resources and the CICS System Definition Guide, SC33-1682 for the System Initialization parameters.

ALT is obsolete, restructuring of CICS eliminates application load table.

DCT Migrate DCT entries to the CSD. It is imperative to use the new DCT supplied definitions. There are some new entries, that if not chosen could cause the disappearance of messages. One such queue is CDUL, where dump information is written.

140VSE to OS/390 Migration Workbook

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IBM OS/390 manual Cics Macro Resource Definition Table Changes

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.