LSF Version 7.3 - Administering Platform LSF

Optimized Preemption of Parallel Jobs
524 Administering Platform LSF
How optimized preemption works
When you run many parallel jobs in your cluster, and parallel jobs preempt other
parallel jobs, you can enable a feature to optimize the preemption mechanism
among parallel jobs.
By default, LSF can over-preempt parallel jobs. When a high-priority parallel job
preempts multiple low-priority parallel jobs, sometimes LSF preempts more
low-priority jobs than are necessary to release sufficient job slots to start the
high-priority job. The optimized preemption mechanism reduces the number of
jobs that are preempted.
Enabling the feature only improves the efficiency in cases where both preemptive
and preempted jobs are parallel jobs. Enabling or disabling this feature has no effect
on the scheduling of jobs that require only a single processor.
Configure optimized preemption
1 Use the PREEMPT_FOR parameter in lsb.params and specify the keyword
MINI_JOB to configure optimized preemption at the cluster level.
If the parameter is already set, the MINI_JOB keyword can be used along with
other keywords; the other keywords do not enable or disable the optimized
preemption mechanism.