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About The IMS Option

The IMS Option enables programmers to manage IMS DB/DC application development under the control of ChangeMan ZMF.

The IMS Option is integrated seamlessly into ChangeMan ZMF. Most of the differences are additional considerations for the ChangeMan ZMF Administrator to define IMS control regions and IMS libraries and library types. The Administrator must also determine what IMS processes are required and when.

The management of IMS components creates several challenges for an automated change management tool. Most of these challenges stem from the need to process (generate or “gen,” as opposed to copying) components as part of the IMS installation process.

ChangeMan ZMF manages installations to production and promotion (test) IMS regions. Once these components are processed, they must be cycled into the IMS execution environment through IMS utilities.

For ChangeMan ZMF to manage IMS installs, additional information about IMS must be defined. For example, ChangeMan ZMF must know what IMS control regions are called, what site ID names have been given to each site, and what promotion nicknames have been created. IMS Option Worksheets contains worksheets to help you gather this information.

Administration Rules

When defining the IMS system libraries, ChangeMan ZMF assumes that the MFS format libraries and ACB libraries are IMS intermediate or staging libraries used for swapping. Although the IMS Option includes skeletons for performing the swaps, most IMS shops already have jobs to do this. You can incorporate these jobs into the promotion and installation processes as defined by your shop’s standards. The IMS Option does not provide a swapping process for format members and ACBs “in place,” as this might cause problems for shops and their database Administrators.

When defining DBD and PSB overrides, you should be aware of the potential impact of doing this at the global, application and package level.

  • Global overrides impact only the installation and baseline ripple remote sites.

  • Application overrides impact all remote sites and override any global defined overrides.

  • Package overrides impact all remote sites and override any global or application- defined overrides.

  • You must check out a component before you can create a package level override for it.

Package Creation Rules

When creating a package, the IMS Option carries forward all active application-defined IMS regions to the package.

Staging Rules

When staging DBD, PSB, or MFS components, the IMS Option assumes that they are being staged with parameters configured for production on the site that they are being staged from. The IMS region information is set to this region provided it is defined.

Otherwise, it is set to the first IMS region defined to the application.

Promotion and Installation Rules

When promoting or installing a package (installing means production installation and baseline rippling), the IMS Option assumes that the promotion, production or baseline libraries differ from the IMS libraries defined in the region definition. The promotion or installation process is configured to sync up the IMS region libraries and promotion or installation libraries.

  • If overrides or GENs are not required, the process copies those members from staging libraries to promotion or installation libraries. Then, it copies those members to the IMS region libraries.

  • If overrides or GENs are required, the members are GENed to the IMS region libraries and then copied to the promotion or installation libraries. If multiple region are associated with this process, the last region in the sequence is used for the copy to promotion or installation libraries.

When demoting or backing out a package, the IMS Option adjusts the promotion and installation libraries accordingly, but the IMS region libraries are untouched. This is done because most MVS™ shops already possess a process for backing out IMS changes and an emergency fix is routinely applied (no back out is required). For promotion, this allows the package to be demoted or promoted to another level without affecting the IMS region.