Access to recoverable VSAM data sets

For a non-CICS application to operate in DFSMStvs mode, begin by requesting RLS processing in either of these ways:

Specify the MACRF=RLS parameter in the ACB macro.
Specify the RLS parameter in the JCL.

In addition, do either of these tasks:

Open a recoverable data set for output from a batch job.
The data set is open for DFSMStvs access if its recoverability attribute, LOG, is set to UNDO or ALL:
LOG=UNDO

Specifies backout logging.

LOG=ALL

Specifies backout logging and forward recovery logging.
Request the CRE read-integrity option in the JCL or through the ACB.

VSAM RLS support enables batch jobs to access recoverable data sets in RLS mode, but only for reading; batch jobs cannot write to these data sets in RLS mode. With DFSMStvs, batch jobs are able to read and write to recoverable data sets while CICS® is concurrently processing those same data sets. A non-CICS application must use RRS to partition the updates done to recoverable VSAM data sets into units of recovery. The application must invoke the RRS commit and backout interfaces to cause points of synchronization. The points of synchronization delineate units of recovery.

If a batch job attempts to communicate with RRS and the system logger goes down, RRS suspends the job until the logger comes back up. If this happens, you cannot cancel the job. To make RRS release the job, you need to bring the system logger back up or take RRS down.