CICS IA interdependency functions

CICS® IA assists in understanding, in a controlled manner, the inter relationships between the shared common resources of applications and services.

Many large organizations have been using CICS since the early 1970s, their systems growing and evolving with the business. During this time, many techniques for implementing applications have been used, as a result of new function, changing corporate standards, technical requirements, and business pressures. Frequently, this growth has not been as structured as it might have been, with the result that many applications and services share common resources, and changes in one area typically affect many others. Unstructured growth can reach such a level that the system can no longer develop in a controlled manner without a full understanding of these inter relationships. CICS IA can help you achieve this understanding.

For example, to change the content or structure of a file, you must know which programs use this file, because they will need to be changed. CICS IA can identify the programs and the transactions that drive the programs.

CICS IA records the interdependencies between resources, such as files, programs, and transactions, by monitoring programming commands that operate on resources. The application that issues such a command has a dependency on the resource named in the command. For example, if an application program issues the command EXEC CICS WRITE FILE myfile it has a dependency on the file called “myfile”. It might have similar dependencies on transient data queues, temporary storage queues, transactions, and other programs.

The commands that are monitored are typically CICS application programming interface (API) and system programming interface (SPI) commands that operate on CICS resources. However, you can also instruct CICS IA to monitor some types of commands that operate on resources that are not CICS. For example: Potentially, the inclusion of any non-CICS resources gives you a fuller picture of the resources used by a transaction.

All the CICS and non-CICS commands that can be monitored are listed in Details of dependencies and affinities collected.

The Collector component of CICS IA collects the dependencies that apply to a single CICS region; that is, a single application-owning region (AOR) or a single, combined routing region and AOR. It can be run against production CICS regions and is also useful in a test environment, to monitor possible dependencies introduced by new or changed application suites or packages. From the interactive interface of CICS IA, you can control Collectors running on multiple regions.

Note: To ensure that you monitor as many potential dependencies as possible, use CICS IA with all parts of your workload, including rarely used transactions and abnormal situations.

CICS IA collects these dependencies into a database. You can store the dependency information from several CICS regions into the same database.

You can review the collected dependencies using the CICS IA Query interface, or list them using the Reporter.

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