IMS Database Recovery Facility

The architecture of IMS Database Recovery Facility (DRF) comprised several key components. The DRF utility itself was the central processing unit, responsible for coordinating the recovery process. It interacted with the IMS log datasets and image copy datasets.

The process began with the creation of image copies using the IMS Image Copy utility. These image copies served as the base for recovery. Transaction logs, generated by IMS, were archived and used by DRF to apply changes to the image copies.

The primary interface for DRF was JCL. JCL scripts defined the recovery jobs, specifying input datasets (image copies and logs) and the desired recovery point. DRF did not expose any APIs.

The DRF utility would read the image copy and apply the relevant log records to bring the database to the specified point in time. DRF used the IMS log datasets for transaction data. DRF's main function was to apply logs to image copies.

DRF is no longer supported; alternative solutions include IBM Db2 Recovery Expert for z/OS, BMC AMI Recover for IMS, and Rocket Software Database Recovery for IMS. These alternatives offer similar functionality with modern features and support.