Change packages
A change package can identify a set of resource definitions that you want to process together, or it can contain a set of commands that you want to process together, or both. You can process a change package to:
- Migrate resource definitions, and the following
commands, between CICS® configurations:
- Add
- You can use the Add command in a change package to perform the
following tasks:
- Add a resource definition to a resource group (ResGroup) in a context-based target CICS configuration
- Add a ResGroup to a ResDesc (by RESINDSC association)
- Add (append) a CSD-based group to a list
- Remove
- You can use the Remove command in a change package to perform
the following tasks:
- Remove a resource definition from a ResGroup
- Remove a ResGroup from a ResDesc (by RESINDSC removal)
- Remove a CSD-based group from a list
- Delete
- You can use the Delete command in a change package to perform
the following tasks:
- Delete a resource definition from either a CSD-based or a context-based target CICS configuration
- Delete a ResGroup from a context-based target CICS configuration (if the ResGroup contains resource definitions, the Delete command fails)
- Delete a group from a CSD-based target CICS configuration (deletes all of the resource definitions in the group)
- Install resource definitions in an active CICS region (the region must either be managed by CICSPlex® SM or be running the CICS Configuration Manager agent)
- Newcopy a program or a document template resource to make a new version of it available to an active CICS region
Discard a change package's resources from an active CICS region or regions
- Back out (undo) changes after migrating
For example, suppose that you are a CICS application developer, and you are enhancing an existing CICS application. The enhancements involve altering existing resource definitions and adding new resource definitions. You have made these changes in your development environment, and now you want to migrate them to your test environment. By adding the altered or new resource definitions to a change package, you can migrate, install, and, if required, back out these changes together. If the enhancements make some existing resource definitions redundant, you can include commands in the change package to delete those resource definitions from the test environment when you migrate the change package from development to test. Backing out the change package "undoes" the delete commands, reinstating the deleted resource definitions to the test environment.
A change package does not contain resource definitions; rather, it contains selection keys that refer to resource definitions stored in a CSD file or a CICSPlex SM context. A selection key identifies a resource definition by its name, group, type, and CICS configuration.
CICS Configuration Manager does not keep its own copy of current resource definitions; these remain in the CSD file or the CICSPlex SM context. However, when you migrate a change package, CICS Configuration Manager writes in its journal "before" and "after" images of the resource definitions from the affected CICS configurations. This enables CICS Configuration Manager to back out migrations.
A change package can contain notes: lines of text written by users, such as special instructions for processing the package.