Requesting automatic restart
Automatic restart occurs only at the latest checkpoint taken. If no checkpoint was taken before interruption, automatic restart occurs at the beginning of the job step.
Whenever automatic restart is to occur, the system repositions all devices except unit-record devices.
If you want automatic restart, code RD=R
or RD=RNC
:
RD=R
indicates that restart is to occur at the latest checkpoint. Code theRERUN
clause for at least one data set in the program in order to record checkpoints. If no checkpoint is taken before interruption, restart occurs at the beginning of the job step.RD=RNC
indicates that no checkpoint is to be written, and that any restart is to occur at the beginning of the job step. In this case,RERUN
clauses are unnecessary; if any are present, they are ignored.
If you omit the RD
parameter, the CHKPT
macro instruction remains active, and checkpoints
can be taken during processing. If an interrupt occurs after the
first checkpoint, automatic restart will occur.
To restart automatically, a program must satisfy the following conditions:
- In the program you must request restart by using the
RD
parameter or by taking a checkpoint. - An abend that terminated the job must return a code that allows restart.
- The operator must authorize the restart.