Requirements for resource preemption

  • Resource preemption depends on all these conditions:

  • The preemption resources must be configured (PREEMPTABLE_RESOURCES in lsb.params).

  • Jobs must reserve the correct amount of the preemption resource, using resource reservation (the rusage part of the resource requirement string).

  • For dynamic preemption resources, jobs must specify the duration part of the resource reservation string.

  • Jobs that use the preemption resource must be spread out among multiple queues of different priority, and preemptive scheduling must be configured so that preemption can occur among these queues (preemption can only occur if jobs are in different queues).

  • Only a releasable resource can be a preemption resource. LSF must be configured to release the preemption resource when the job is suspended (RELEASE=Y in lsf.shared, which is the default). You must configure this no matter what your preemption action is.

  • LSF’s preemption behavior must be modified. By default, LSF’s default preemption action does not allow an application to release any resources, except for job slots and static shared resources.