Program code to execute at restart

It might be necessary to write some code, such as priming application program variables, to execute when an application program is restarted. For example, a page counter might need to be incremented. If the last page of a report written before failure was 153, the next page after restart will be 154 and the application program might need to pre-increment the page counter. This type of code is specific to the application program and usually requires individual analysis of each program to ensure proper restartability.

When the application program issues the restart call, AR/CTL repositions the data sets that are using AR/CTL data services. However, if a COBOL program accesses a KSDS through an alternate index (AIX), the program must reestablish its position to the appropriate key in the AIX by using the key information in a data area saved during checkpoint processing.

If the application program is using DB2, the application program must reposition the DB2 tables by using the key information in a data area saved during checkpoint processing. If the application program already contains restart logic for IMS restart, no change is necessary.

The application program must issue an OPEN request after the restart ( ARCXRST or XRST ) call for any file that AR/CTL accesses through dynamic call interception (sequential file interception, local VSAM access, and remote VSAM access services).

Program code to execute at restart

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