Platform LSF Administration Guide Version 6.2

Chapter 29
Runtime Resource Usage Limits
Administering Platform LSF
465
◆ PROCESSLIMIT
◆ RUNLIMIT
◆ THREADLIMIT
Host specification
with two limits
If default and maximum limits are specified for CPU time limits or run time limits, only
one host specification is permitted. For example, the following CPU limits are correct
(and have an identical effect):
◆ CPULIMIT = 400/hostA 600
◆ CPULIMIT = 400 600/hostA
The following CPU limit is not correct:
CPULIMIT = 400/hostA 600/hostB
The following run limits are correct (and have an identical effect):
◆ RUNLIMIT = 10/hostA 15
◆ RUNLIMIT = 10 15/hostA
The following run limit is not correct:
RUNLIMIT = 10/hostA 15/hostB
Default run limits for backfill scheduling
Default run limits are used for backfill scheduling of parallel jobs.
For example, in
lsb.queues, you enter: RUNLIMIT = 10 15
◆ The first number is the default run limit applied to all jobs in the queue that are
submitted without a job-specific run limit (without
bsub -W).
◆ The second number is the maximum run limit applied to all jobs in the queue that
are submitted with a job-specific run limit (with
bsub -W). The default run limit cannot exceed the maximum run limit.
Automatically assigning a default run limit to all jobs in the queue means that backfill
scheduling works efficiently.
For example, in
lsb.queues, you enter:
RUNLIMIT = 10 15
The first number is the default run limit applied to all jobs in the queue that are
submitted without a job-specific run limit. The second number is the maximum run
limit.
If you submit a job to the queue without the -
W option, the default run limit is used:
% bsub myjob
The job myjob cannot run for more than 10 minutes as specified with the default run
limit.
If you submit a job to the queue with the
-W option, the maximum run limit is used:
% bsub -W 12 myjob
The job myjob is allowed to run on the queue because the specified run limit (12) is less
than the maximum run limit for the queue (15).
% bsub -W 20 myjob
The job myjob is rejected from the queue because the specified run limit (20) is more
than the maximum run limit for the queue (15).