Forward Recovery System

The architecture of the Forward Recovery System (FRS) is centered around three primary components: the Recovery Manager, the Journal Reader, and the File Updater. The Recovery Manager is the central control unit, coordinating the recovery process. It receives commands, manages the recovery workflow, and interacts with the other components.

The Journal Reader is responsible for reading the journal data, which contains the changes made to the VSAM files. It parses the journal records and provides the data to the File Updater. The File Updater applies the journal records to the VSAM files, effectively restoring them to a consistent state.

Communication between these components is primarily internal, using standard z/OS and zVSE/VSEn inter-process communication mechanisms. The Recovery Manager initiates and monitors the Journal Reader and File Updater processes. The Journal Reader reads data from the journal datasets, which are typically VSAM files themselves.

The File Updater then applies these changes to the target VSAM files. The system does not use external databases for its core operations, relying instead on the VSAM files and journal datasets. Network requirements are minimal, as the components primarily communicate within the z/OS or zVSE/VSEn environment.

The system uses standard z/OS and zVSE/VSEn protocols for internal communication. The configuration files define the parameters for recovery, including file names, journal dataset names, and recovery options. The `START RECOVERY` command initiates the recovery process, and the `STATUS` command provides real-time monitoring of the recovery progress.

FRS does not expose APIs. The system supports authentication to control access to recovery operations and provides detailed audit logging for tracking activities. Compared to manual recovery, FRS automates the process, reducing downtime and data loss risk.