Setting up CICS VR change accumulation

CICS® VR CA reduces the time it takes to perform a forward recovery.

CICS VR CA consolidates forward recovery log records into a CA data set. CICS VR uses the CA data set in conjunction with the forward recovery log to reduce the number of log records that CICS VR needs to apply to return the sphere to the exact state before the data was lost.

CICS VR change accumulation consolidates all log records written for VSAM spheres since their latest backups were taken. The consolidated log records are then written to a change accumulation data set. For example, if 100 updates were made to the same record in a VSAM sphere, this would produce 100 after-image log records. CICS VR change accumulation processing can then sort and filter these log records, copying only the most recent after-image into the CA data set. CICS VR then can use this CA data set (instead of reading the 100 after-images) during forward recovery processing.

CICS VR CA processing only processes log records written since the latest backups were taken for the spheres. When CICS VR finds that new backups have been taken for VSAM spheres, the old CA data sets for the spheres are invalidated. If CICS VR is aware of logical backups that are taken for the spheres, the process of invalidating outdated CA data sets is automated. If CICS VR is not aware of backups created for the spheres, the latest backup dates and times must be manually entered into the CA batch jobs before execution.
Note: CICS VR is aware of logical backups if they have either been registered in the CICS VR RCDS through backup notification, or if they are registered in DFSMShsm's inventory.

CA is a two step process. The next two sections cover both of these steps.


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Timestamp icon Last updated: Friday, 29 November 2013


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