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.

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. The second number is the maximum run limit.

If you submit a job to the queue without the -W option, the default run limit is used:
bsub myjob

The job myjob cannot run for more than 10 minutes as specified with the default run limit.

If you submit a job to the queue with the -W option, the maximum run limit is used:
bsub -W 12 myjob

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).

bsub -W 20 myjob

The job myjob is rejected from the queue because the specified run limit (20) is more than the maximum run limit for the queue (15).