Platform LSF Administration Guide Version 6.2

Chapter 14
Preemptive Scheduling
Administering Platform LSF
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Jobs from low_q1 are preferred first for preemption before jobs from low_q2 and
low_q3.
If preemptable queue preference and preemption on jobs with least run time are both
enabled, the queue preference for the job is considered first, then the job run time.
Preempting jobs with the least run time
By default, when more than one preemptable job exists (low-priority jobs holding the
required job slots), LSF preempts a job from the least-loaded host.
You can configure LSF to consider the jobs with least run time first instead of choosing
jobs based on least-loaded host. Run time is wall-clock time, not normalized run time.
If preemptable queue preference and preemption on jobs with least run time are both
enabled, the queue preference for the job is considered first, then the job run time.
Configuring
preemption on
least run time
Set PREEMPT_FOR in lsb.params, and use the LEAST_RUN_TIME keyword to
indicate that jobs with the least run time are to be preempted before other jobs.
Preventing preemption by run time
You can configure LSF to prevent preemption of a job that would finish within a
specified time or that has been running for a specified time. Run time is wall-clock time,
not normalized run time.
You must define a run limit for the job, either at job level by
bsub -W option or in the
queue by configuring RUNLIMIT in
lsb.queues.
NO_PREEMPT_RUN_TIME, NO_PREEMPT_FINISH_TIME (lsb.params)
Set NO_PREEMPT_RUN_TIME in lsb.params, and the jobs have been running
for the specified number of minutes or longer will not be preempted.
Set NO_PREEMPT_FINISH_TIME in
lsb.params, and jobs that will finish within
the specified number of minutes will not be preempted.