Preemption
Preemption is the process of reserving or revoking resources from other jobs in order to help "important jobs" finish quickly.
It is normally triggered by queued jobs, but can also be triggered by a change in a resource or by a manual request from the user. Preemption may require killing or suspending running jobs, but it can also be "gentle," only generating events or reserve resources such as taskers or licenses.
The queued job that triggers preemption is called the preempting job, while the job or jobs from which the resources are revoked are called the preempted jobs.
Preemption can be used with licenses that are constantly used by background regression jobs. This way, engineers who need licenses for interactive jobs do not have to wait for a regression job to finish.
Preemption Directory and Files
- Working directory
- vnc.swd/vovpreemptd
- Config file
- vnc.swd/vovpreemptd/config.tcl
- Info file
- vnc.swd/vovpreemptd/info.tcl
- Aux directory
- vnc.swd/preemption
Monitoring Preemption Behavior
To monitor the behavior of the preemption mechanism, view the Preemption Status page.
You may also find it helpful to run separate Accelerator GUIs, one for the set of preemptable jobs, one for the set of preempting jobs, etc. This setup enables observing jobs that enter the system, jobs that are preempted, and other jobs that are running with the new resources.