CA Jobtrac Job management r11: How to detect loops in a successor chain

Document ID : KB000049961
Last Modified Date : 14/02/2018
Show Technical Document Details


This Knowledge Document explains how to detect loops within a schedule issuing 'Loop Detected' or 'Limit Reached. Loop?'.


CA Jobtrac JM currently offers two methods to detect successor loops:

The 'L' line command and the (sample REXX) Imod LOOPDET as explained below.

  1. The 'L' line command:

    The primary purpose of this Scheduled Event Network panel is to list all the event's predecessors and successors. If an event belonging to a loop is selected, then message "Loop Detected" is issued. If there's a loop, but the selected event doesn't directly belong to it, then the message "Limit Reached. Loop?" is issued.

  2. Imod LOOPDET:

    Because of the recursive call of an internal subroutine, the online execution (SRVEDIT or JOBTRAC) may result in error message SRV277/GRX0011I (with "Control stack full"), so it is best to run in batch. It either issues message "LOOPDET00 CHECKPOINT VERIFIED: NO LOOPS" or "LOOPDET99 LOOP HAS BEEN DETECTED: SUCCESSOR CHAIN FOLLOWS". The JCL for the batch job is as follows:
     //jobname   JOB . . . your accounting data . . .        //STEP1    EXEC PGM=SRVBATCH,PARM='LOOPDET'  //STEPLIB    DD DISP=SHR,DSN=your.Jobtrac.CAILIB //           DD DISP=SHR,DSN=your.GSS.CAILIB //           DD DISP=SHR,DSN=your.DATACOM.CUSLIB //           DD DISP=SHR,DSN=your.DATACOM.CAILIB //IMOD       DD DISP=SHR,DSN=your.sample.REXX.ISET.file //JOBTRACx   DD DUMMY with 'x' as your Jobtrac Token //PARMLIB    DD *   ADDRESS JOBTRAC GJTRGCUU 15 MAXTASK 5 TYPE 3 //ISRVLOG    DD SYSOUT=* //OUTPUT     DD SYSOUT=* //