How can programs SASSTRLR (trailer step) or U7SVC command(s) process twice in CA 7?

Document ID : KB000025201
Last Modified Date : 14/02/2018
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Summary: 

This document explains how program SASSTRLR (trailer step) or U7SVC command(s) can be processed twice by CA 7.

Instructions: 

The programs SASSTRLR (trailer step) and U7SVC can be used to pass command(s) to CA 7 from a batch job or program. SASSTRLR or U7SVC programs write the CA 7 command(s) in CSA and ICOM gets the command(s) from CSA and writes them to the Communications Data Set (UCC7CMDS DD in CA 7/ICOM procedure). In the UCC7CMDS file, there are fields that contain offsets within the file where ICOM 'last wrote to' and where CA 7 'last read from'. When ICOM writes trailer data to the UCC7CMDS file, it updates its 'last written to' offset which CA 7 is reading to see if it has trailer data to process (if the 'last read from' and the 'last written to' are not equal, there is data to process). If CA 7 is cancelled or abends at the specific time it has picked up command(s) from the UCC7CMDS file and before it updates the 'last read from' offset, when CA 7 comes back up, it will process the command(s) again. CA 7 should always be shutdown cleanly with the /SHUTDOWN command.

Additional Information:

As always, please contact CA Technologies support for CA 7 if you have further questions.