For reliable restart, checkpoint services must be requested at least once before normal application program termination.
Through the automatic checkpoint options, AR/CTL can request checkpoint services automatically on behalf of the program by defining a trigger or issuing a Db2 commit, or the program can request checkpoint services by issuing a checkpoint call in one of several formats. AR/CTL can monitor whether checkpoint services are used during execution of an application program.
If checkpoint services are not requested, AR/CTL can issue a warning message or issue an abend.
ErrorWarning
The ABEND value of this option does not prevent database updates because
AR/CTL
issues the abend during termination. This value may cause an application program that would otherwise terminate normally to require recovery and reprocessing. However, using this value and accepting its consequences may help prevent future problems caused by the lack of checkpoint services. You can use the Check IMS Updates option to prevent the application program from updating DL/I databases without first requesting the appropriate services.
In addition to the warning or abend, AR/CTL for IMS can convert IMS basic checkpoints to symbolic checkpoints if AR/CTL encounters at least one basic checkpoint and the program has not issued the XRST (extended restart) call. This action allows a program that issues basic checkpoints to execute as successfully with AR/CTL as without AR/CTL. However, because no XRST call has been issued, the application program is not restartable.
ErrorWarning
BMC Software recommends that you avoid using
AR/CTL
for an application program that issues IMS basic checkpoints because
AR/CTL
can provide no benefits but adds considerable overhead to the execution. You can use any of several techniques to deactivate
AR/CTL
, including automatic creation of an IMS program exclusion record. For more information about excluding
AR/CTL
, see Using.
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| Set one of the following values: N in ISPF; NO in ARCSYSIN | Do not monitor the use of checkpoint services during execution. | W in ISPF; WARN in ARCSYSIN | Issue warning message BMC74055E if checkpoint services are not requested at least once before normal application program termination. | A in ISPF; ABEND in ARCSYSIN | At job step termination, issue a user 1771 abend if checkpoint services are not requested at least once before normal application program termination. | WC or CW in ISPF; (WARN,CONVERT) or (CONVERT,WARN) in ARCSYSIN | Issue warning message BMC74055E if checkpoint services are not requested at least once before normal application program termination. In addition, if the program issues an IMS basic checkpoint without issuing an IMS XRST call, convert the basic checkpoint to a symbolic checkpoint. | AC or CA in ISPF; (ABEND,CONVERT) or (CONVERT,ABEND) in ARCSYSIN | At job step termination, issue a user 1771 abend if checkpoint services are not requested at least once before normal application program termination. In addition, if the program issues an IMS basic checkpoint without issuing an IMS XRST call, convert the basic checkpoint to a symbolic checkpoint. |
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