Predictive Recall (MON-PRECALL) extracts information from Job Scheduler systems and examines the scheduled job streams to create a list of production datasets that will be accessed in the during next production cycle. If any of the datasets have been migrated, appropriate HRECALL commands are generated and passed directly to the Inactive Data Mover. To avoid any impact on the production workload, the MON-PRECALL job can be scheduled to run when the system is under-utilized prior to the production cycle.
The costly problems
Unscheduled production dataset recalls will delay the production cycle since the job will be required to wait for the dataset to be recalled. The delay can be significant, especially for large files. If there is no VTS, there will be additional delays for tape location, mounting and dataset recovery.
To avoid these delays, a common and costly practice is to set high migration age levels to ensure the dataset will be available. This inefficient practice keeps production datasets unnecessarily on active DASD, resulting in higher storage costs.
With Predictive Recall, the migration age could be set efficiently, e.g., a few days. A dataset used infrequently will be migrated quickly, freeing up DASD space, and then later recalled by the Predictive Recall application shortly before it is actually needed.
How does it work?- The Job Scheduling software generates a list of the jobs for the Predictive Recall application to consider
- The actual JCL used in the production jobs is obtained and the JCL is expanded to determine the fully qualified dataset names that will be used for the production run
- A catalog lookup is issued for each input dataset, and a HRECALL statement is generated if the VOLSER is MIGRAT
- The HRECALL statements are passed directly to the Inactive Data Mover to recall the dataset prior to the production cycle
What job schedulers are supported?
The Predictive Recall software provides support for the major Job Schedulers:
- CA7
- Control-M
Additional job schedulers can be supported by sending a sample scheduler report for the jobs that are scheduled to run during a batch window.
What inactive data movers are supported?
The application supports both DFHSM and FDR/ABR. If support for another Inactive Data Mover is required, a simple change to the Monitor control cards can be implemented to generate a different HRECALL command format.
The recall thrashing reports
For DFHSM customers, MON-PRECALL provides reports showing the number of recalls occurring per hour throughout the day, or a daily summary report to target specific days of the month like month-end processing. The reports can be filtered to show only production recalls if those recalls can be identified by high level qualifier.