Advanced Topics › Enqueue Conflict Management Facility › How ECMF Handles Requeued Jobs When CA MIM Terminates › Compatibility with Job Scheduling Packages

Compatibility with Job Scheduling Packages

CA MII is compatible with all scheduling packages. CA 7 customers should specify REQUE=YES in CA 7. The default for this parameter is NO.

However, ECMF REQUEUE was not designed to aid in job scheduling and does not replace the need for a job scheduling package. After a job is requeued, resource availability is only determined at fixed intervals (SET ECMF REQCYCLE). So, it is possible that other jobs can “sneak in” and obtain resources that were needed by the requeued job, during the interim.

For example, with REQCYCLE=30:

mm:ss

00:00 JOBA requeued, 2 of 7 data sets were not available

00:30 REQCYCLE timer pops

• ECMF checks availability of all 7 data sets
• Now only 1 data set is not available (DATASET1) JOBB owns this
• JOBA not released

01:00 REQCYCLE timer pops

• ECMF checks availability of all 7 data sets
• Data set 1 still owned by JOBB
• JOBA not released

01:05 JOBB ends and releases DATASET1

01:10 JOBC starts and obtains DATASET1

01:30 REQCYCLE timer pops

• ECMF checks availability of all 7 data sets
• JOBC now owns DATASET1
• JOBA still not released

01:40 JOBC ends and releases DATASET1

02:00 REQCYCLE time pops

• ECMF checks availability of all 7 data sets
• All 7 are now available
• JOBA is released

Though JOBC was started after JOBA, it finished before JOBA. Thus, ECMF REQUEUE cannot be used as a scheduling package, and the order in which the jobs run may or may not be first in, first out.