With automatic checkpoint-restart, the operating system will ask the operator whether an unsuccessful/abending step should be restarted. A “yes” reply instructs the system to restart the job at the last checkpoint taken. If the operator replies “no,” the job will still be eligible for deferred checkpoint-restart, but its control statements will have to be modified before the job is resubmitted.
The requirements for automatic checkpoint-restart are:
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The sort step must have a unique name.
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The JOB statement must specify RD=R and MSGLEVEL=1.
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All system completion codes with which the sort may abend should be defined at system generation time as being eligible for restart. If the RC16=ABE and/or IOERR=ABE options are in effect, for example, then user abend codes 16 and/or 999 must be eligible for restart.
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User-written exit routines and calling programs may not issue the STIMER macro.
Figure 1. Sample Automatic Checkpoint-Restart JCL Stream