Backup phase

Figure 1 shows the backup phase.

Figure 1. Package Backout—Backup Phase

                  1. Save
┌────────────┐   ───────────►
│            │
│    Prod    ├──────────────────────┐
│            │                      │
└──────┬─────┘                ┌─────┴──────┐
       │                      │            │
       │ ↑                    │   Backup   │
       │ │ 3. Promote         │            │
       │ │                    └────────────┘
       │
┌──────┴─────┐               2. Package details file updated
│            │
│  Pre-Prod  │
│            │
└──────┬─────┘
       │
       │
       │
┌──────┴─────┐
│            │
│    Test    │
│            │
└──────┬─────┘
       │
       /
       /

Package details are maintained as members of the Package Details file PDS. This PDS needs to be defined by the SCLM Administrator.

The SCLM type for this PDS is nominated using the FLMTYPE macro, for example:

BACKUP   FLMTYPE PACKFILE=Y

These PDS members hold the package backout information, such as:

Package status
Group
Type
Member
Old member timestamp
New member timestamp
Timestamp when backed out
Member status
Member-level selection flag

Accounting records of the non-editable types are not saved back to the backup level, nor restored to the higher group.

Any subsequent package promotion that involves the same type/member invalidates the ability of the member from the original package to be restored, and causes the member to be overwritten in the backup data set. The member cannot be restored, because the physical timestamp of the member differs from the timestamp in the Package Details file. The Package Backout routines check timestamps dynamically, to ascertain if the member is still eligible for restore processing.

A promote that involves a package that can be backed out can be restarted. If it is, the package members being backed up are simply recopied during the restarted promote.

Specifying the parameter REUSEDAY=nnnn forces SCLM to check the package date in the Package Details File for the package being promoted. If this package is not younger than the REUSEDAY value, then the package details member is deleted. If it is younger than the value then SCLM reuses the package. With Package reuse, if the module is being promoted again it overwrites the older backed up version of that module.