Change lists for the IMSRSC repository

IMS warm or emergency restart processes the IMS log to build runtime resource definitions. After the log is processed, if IMS is enabled to use the IMSRSC repository, IMS calls Resource Manager (RM) to read any change list for the IMS.

The keywords SCOPE(ALL) and SCOPE(ACTIVE) for the IMPORT DEFN command identify whether the command applies to all IMS systems in which the resource is defined or only to the active systems.

If stored resource definitions are imported by an IMPORT DEFN SCOPE(ALL) command and an IMS system for which the resource definitions are defined is not active, a change list is created by the RM for that IMS in the repository. A change list consists of resource and descriptor names and types that are to be imported when the IMS system restarts.

If IMS is enabled to use the repository, IMS calls Resource Manager (RM) during warm start or emergency start to read any change list for the IMS. If a change list exists for the IMS that is being restarted, the database, program, transaction, and routing code resources and descriptors in the IMS change list and that apply to the IMS environment are quiesced and are not available for use until the stored resource definitions are imported from the repository. After the IMS log is processed, IMS imports the stored resource definitions from the repository for the database, program, transaction, and routing code resources and descriptors in the IMS change list. It then applies the changes to the runtime resource and descriptor definitions in the IMS. For the resources or descriptors that are in the IMS change list and that do not exist in IMS, the runtime resource definitions are created from the stored resource definitions in the repository. For the resource or descriptors that exist in IMS, the runtime resource definitions are updated with the stored resource definitions from the repository. The change list for the IMS system is deleted at the end of the cold, warm, or emergency restart.