How FRS works
Forward Recovery System runs as a batch job OUTSIDE of your CICS system. NO MODIFICATIONS are required to CICS or CICS programs.
Forward Recovery System uses a job requiring a minimum of JCL to ease the effort involved in recovering a production CICS KSDS, RRDS, or ESDS VSAM dataset.
Input to the job is a set of simple control records (commands) that identify the file involved, the transaction(s) involved, the beginning and ending time(s) and date(s), and/or the terminal(s) creating the changes to the file.
To identify which data is on a particular CICS Journal file, a CHECK (or scan) may be made where no data is moved, but a report is generated showing the number of changes for the desired file(s) on this journal, and optionally the details of each of these changes. This capability becomes very important in the case of corruption and can be invaluable when multiple files are involved.