Platform LSF Administration Guide Version 6.2

Chapter 13
Deadline Constraint and Exclusive Scheduling
Administering Platform LSF
249
Using Exclusive Scheduling
Exclusive scheduling gives a job exclusive use of the host that it runs on. LSF dispatches
the job to a host that has no other jobs running, and does not place any more jobs on
the host until the exclusive job is finished.
How exclusive scheduling works
When an exclusive job (bsub -x) is submitted to an exclusive queue (EXCLUSIVE =
Y in
lsb.queues) and dispatched to a host, LSF locks the host (lockU status) until
the job finishes.
LSF cannot place an exclusive job unless there is a host that has no jobs running on it.
To make sure exclusive jobs can be placed promptly, configure some hosts to run one
job at a time. Otherwise, a job could wait indefinitely for a host in a busy cluster to
become completely idle.
An exclusive job cannot preempt another job, and cannot be preempted by another job.
Configuring an exclusive queue
To configure an exclusive queue, set EXCLUSIVE in the queue definition
(
lsb.queues) to Y.
Configuring a host to run one job at a time
To make sure exclusive jobs can be placed promptly, configure some single-processor
hosts to run one job at a time. To do so, set SLOTS=1 and HOSTS=all in
lsb.resources.
Submitting an exclusive job
To submit an exclusive job, use the -x option of bsub and submit the job to an
exclusive queue.