Understanding CICS VR forward recovery logging

CICS® VR forward recovery logging writes an after-image log record to a forward recovery log stream for every update made to a VSAM data set by a batch job. Therefore, if a VSAM data set become corrupt, you can use CICS VR forward recovery processing to recreate the batch updates.

When a batch job starts, CICS VR obtains the name of the forward recovery log stream specified in the LOGSTREAMID field in the catalog entry of the VSAM sphere. CICS VR then stores information about this log stream in the RCDS and proceeds to write after-image log records to the log stream.

CICS VR can create forward recovery log data in a single system environment or a multiple system sysplex environment connected through the coupling facility.

When the forward recovery log data is written through the coupling facility, the MVS system logger automatically merges online output with the log stream by log stream name. It does not matter which system in the sysplex the log stream came from.

The RCDS must be allocated to a recover job for batch REDO after images unless the recover being run also specifies the REMOTE keyword.