Default run limits for backfill scheduling

Default run limits are used for backfill scheduling of parallel jobs.

For example, in lsb.queues, you enter: RUNLIMIT = 10 15
  • The first number is the default run limit applied to all jobs in the queue that are submitted without a job-specific run limit (without bsub -W).
  • The second number is the maximum run limit applied to all jobs in the queue that are submitted with a job-specific run limit (with bsub -W). The default run limit cannot exceed the maximum run limit.

Automatically assigning a default run limit to all jobs in the queue means that backfill scheduling works efficiently.

If you submit a job to the queue with the -W option, (bsub-W 12 myjob) the maximum run limit is used. The job myjob is allowed to run on the queue because the specified run limit (12) is less than the maximum run limit for the queue (15).

However, if the specified run limit is greater than the run limit for the queue (15) (for example, bsub-W 20 myjob), then the job will be rejected from the queue.