The JOB_CONTROL process is the VMS Job controller process.
Image Location: SYS$COMMON:[SYSEXE]JBC$JOB_CONTROL.EXE
Job controller process functional summary
The job controller performs multiple functions for VMS:
- When a new terminal connection is detected the job controller creates a process attached to the terminal running LOGINOUT.EXE to initiate the login process.
- Processes all VMS requests to write accounting data to the system accounting file.
- Acts as the client communication to all VMS Queue Managers running in a cluster.
- Creates batch processes and symbiont processes on the local system.
- Notifies queue managers of the batch job and symbiont processes terminations on the local system.
- Creates queue manager processes for queue managers that are prioritized to run on the local system.
- Performs Standard Time and Daylight Saving Time clock adjustments, when the system parameter AUTO_DLIGHT_SAV is 1.
- As a known, persistent process JOB_CONTROL is sometimes used by products and OS components as the target to queue ASTs to perform a desired actions. For example, the Availability Manager Product has an option to force crash a system. The Availability Manager RMDRIVER queues an AST to the JOB_CONTROL process to perform the crash.
Job controller communication
The job controller receives messages to perform operations through two methods:
- Job Control permanent Mailbox MBA1:
- IPC Queue Manangement Association Channel <association name to be supplied>