Browse Prior Art Database

Job Recovery Journal

IP.com Disclosure Number: IPCOM000075238D
Original Publication Date: 1971-Aug-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Kaplan, MP: AUTHOR

Abstract

In the operation of a data processing system, scheduler control blocks CB's are resident in a scheduler work area SWA of main storage. A job journal is maintained in auxiliary storage to provide a warm start capability in the event of a system failure. To do this, information is written into the journal by a JOURNAL WRITER routine and is read therefrom by a JOB RECOVERY routine.

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Job Recovery Journal

In the operation of a data processing system, scheduler control blocks CB's are resident in a scheduler work area SWA of main storage. A job journal is maintained in auxiliary storage to provide a warm start capability in the event of a system failure. To do this, information is written into the journal by a JOURNAL WRITER routine and is read therefrom by a JOB RECOVERY routine.

The journal is a data set opened during job initiation prior to interpretation and closed during job termination. It contains the minimum information necessary to perform device unallocation and termination for a failing job. Information is placed in the journal by the writer dependent on the status of the job step as to whether it is going through allocation, execution or termination. No journalling is done during interpretation because the control statements (JCL) are saved.

Should a system failure occur, the recovery routine uses the information in the journal to create a new SWA and reconstruct the CB's therein to contain the information present just prior to failure. This is done by reinterpreting the JCL and recreating the original CB's. Then, entries in the journal will be merged with the CB's. The job will then be terminated, freeing SWA, and a determination will be made as to whether the job can be restarted. If it can, then the job is placed in a work queue and will be restarted by using the journal and JCL or by using checkpoint restart if it is available....