Platform LSF Administration Guide Version 6.2

Using Deadline Constraint Scheduling
Administering Platform LSF
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Using Deadline Constraint Scheduling
Deadline constraints will suspend or terminate running jobs at a certain time. There are
two kinds of deadline constraints:
◆ A run window, specified at the queue level, suspends a running job
◆ A termination time, specified at the job level (bsub -t), terminates a running job
Time-based resource usage limits
◆ A CPU limit, specified at job or queue level, terminates a running job when it has
used up a certain amount of CPU time.
◆ A run limit, specified at the job or queue level, terminates a running job after it has
spent a certain amount of time in the RUN state.
How deadline constraint scheduling works
If deadline constraint scheduling is enabled, LSF will not place a job that will be
interrupted by a deadline constraint before its run limit expires, or before its CPU limit
expires, if the job has no run limit. In this case, deadline constraint scheduling could
prevent a job from ever starting. If a job has neither a run limit nor a CPU limit, deadline
constraint scheduling has no effect.
Deadline constraint scheduling only affects the placement of jobs. Once a job starts, if
it is still running at the time of the deadline, it will be suspended or terminated because
of the deadline constraint or resource usage limit.
Disabling deadline constraint scheduling
Deadline constraint scheduling is enabled by default. To disable it for a queue, set
IGNORE_DEADLINE=y in
lsb.queues.
Example
LSF will schedule jobs in the liberal queue without observing the deadline
constraints.
Begin Queue
QUEUE_NAME = liberal
IGNORE_DEADLINE=y
End Queue