Deferred Checkpoint-Restart - mfx - 3.1

Syncsort™ MFX Programmers Guide

Product type
Software
Portfolio
Integrate
Product family
Syncsort™ Software
Product
Syncsort™ MFX > MFX
Version
3.1
Language
English
Content type
Programmer’s Guide
Product name
Syncsort™ MFX
Title
Syncsort™ MFX Programmers Guide
Copyright
2024
First publish date
2010
Last updated
2024-11-06
Published on
2024-11-06T17:38:26.716054

Unlike automatic checkpoint-restart, deferred checkpoint-restart requires that certain JCL changes be made before resubmitting the job.

The requirements for a deferred restart are:

  • A SYSCHK DD statement must appear immediately before the first EXEC statement in the job. The SYSCHK DD must use the same DSN name as the SORTCKPT DD of the sort that failed. Specify UNIT, VOL=SER, and DISP=(OLD,KEEP).

  • The RESTART parameter must be specified, and must provide the job stepname and the PROC stepname (if any) associated with the step containing the failed sort, as the first subparameter. (Separate the two stepnames by a period.) The second subparameter should contain the checkpoint ID of the last checkpoint taken before the sort failed. This can be determined from the console messages given for the job. For JCL sorts, the ID is usually "Cnnnnnnn," referring to the sequence number assigned by the operating system.

  • SORTIN and SYSIN DD DUMMY statements are permissible if the program is being restarted at a point where they are no longer needed.

    Figure 1. Sample Deferred Checkpoint-Restart JCL Stream

    This JCL differs from automatic checkpoint-restart JCL.