Administering Platform LSF - SAS

Chapter 12
Preemptive Scheduling
Example
◆
For queues without a preference number, the queue with lower-priority is
preferred than the queue with higher priority
Begin Queue
QUEUE_NAME = high_priority
PRIORITY = 50
PREEMPTION = PREEMPTIVE[low_q1+2 low_q2 low_q3]
End Queue
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
Configuring
preemption on
least run time
By default, when more than one preemptable job exists (low-priority jobs
holding the required resource), 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.
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 wallclock
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.
Administering Platform LSF 183