Fast DB Recovery region in DB/DC

The Fast DB Recovery region is a separate IMS control region that monitors an IMS, detects failure, and recovers any IMS-owned database resources that are locked by the failed IMS, making them available for other IMS systems without having to wait for the next full restart.

For database resources that are not IMS owned, such as Db2 for z/OS® databases, the Fast DB Recovery region provides an optional exit routine, ESAF In-Doubt Notification exit routine (DFSFIDN0), for this purpose.

The Fast DB Recovery region is executed by the cataloged procedure that is supplied by IMS system definition. You must start the Fast DB Recovery region after you start the IMS that it tracks.

To enable a DB⁄DC IMS for Fast DB Recovery, specify the FDRMBR parameter in the IMS procedure. The FDRMBR parameter defines the DB⁄DC system as Fast DB Recovery-capable.