LSF Version 7.3 - Administering Platform LSF

Administering Platform LSF 277
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Preemptive Scheduling
Contents
◆ About Preemptive Scheduling on page 277
About Preemptive Scheduling
Preemptive scheduling lets a pending high-priority job take job slots away from a
running job of lower priority. When two jobs compete for the same job slots, LSF
automatically suspends the low-priority job to make slots available to the
high-priority job. The low-priority job is resumed as soon as possible.
Use preemptive scheduling if you have long-running low-priority jobs causing
high-priority jobs to wait an unacceptably long time.
For detailed information about the preemptive scheduling feature and how to
configure it, see the Platform LSF Configuration Guide.
Limitation
By default, the following types of jobs cannot be preempted:
◆ Jobs that have been forced to run with the command brun
◆ Backfill and exclusive jobs
Preemptive and preemptable queues
Preemptive queues Jobs in a preemptive queue can preempt jobs in any queue of lower priority, even if
the low-priority queues are not specified as preemptable.
Preemptable
queues
Jobs in a preemptable queue can be preempted by jobs from any queue of a higher
priority, even if the high-priority queues are not specified as preemptive.
Preemptive and preemptable jobs
Preemptive jobs Preemptive jobs are pending in a high-priority queue and require the specified job
slots. Their queue must be able to preempt the low-priority queue.