Kraken uses MOAB/TORQUE to schedule jobs. NICS is constantly reviewing the scheduling policies in order to adapt and better serve users.
Because of the unique large computing capacity of Kraken, the scheduler will give preference to large core count jobs. Moab is configured to do “first fit” backfill. Backfilling allows smaller, shorter jobs to use otherwise idle resources.
Although users can manually alter the queued jobs, the priority of jobs will be highly dependent on the following factors:
- waiting time in the queue--the priority goes up as a job continues to wait.
- number of cores requested--jobs that request more cores get a higher priority.
- wall clock time requested--jobs with shorter wall clock limits get higher priority.
- account balance--jobs that use an account with a negative balance will have the lowest priority. These jobs will only run as backfill jobs.
- limit of eligible jobs--a maximum of five jobs per user, at a time, will be eligible to run. The rest will be blocked.
Note: In certain special cases, the priority of a job may be manually increased upon request. To request priority change you may contact NICS User Support. NICS will need the job ID and reason to submit the request.
