Administering Platform LSF - SAS

Configuring Pre- and Post-Execution Commands
Configuring Pre- and Post-Execution Commands
Job-level commands
Example
Queue-level commands
Pre- and post-execution commands can be configured at the job level or on a
per-queue basis.
Job-level pre-execution commands require no configuration. Use the bsub -E
option to specify an arbitrary command to run before the job starts.
The following example shows a batch job that requires a tape drive. The user
program tapeCheck exits with status zero if the specified tape drive is ready:
% bsub -E "/usr/share/bin/tapeCheck /dev/rmt01" myJob
Use the PRE_EXEC and POST_EXEC keywords in the queue definition
(lsb.queues) to specify pre- and post-execution commands.
The following points should be considered when setting up pre- and postexecution
commands at the queue level:
◆ If the pre-execution command exits with a non-zero exit code, then it is
considered to have failed and the job is requeued to the head of the queue.
This feature can be used to implement customized scheduling by having
the pre-execution command fail if conditions for dispatching the job are
not met.
◆ Other environment variables set for the job are also set for the pre- and
post-execution commands.
◆ When a job is dispatched from a queue which has a pre-execution
command, LSF will remember the post-execution command defined for the
queue from which the job is dispatched. If the job is later switched to
another queue or the post-execution command of the queue is changed,
LSF will still run the original post-execution command for this job.
◆ When the post-execution command is run, the environment variable,
LSB_JOBEXIT_STAT, is set to the exit status of the job. See the man page
for the wait(2) command for the format of this exit status.
◆ The post-execution command is also run if a job is requeued because the
job’s execution environment fails to be set up, or if the job exits with one
of the queue’s REQUEUE_EXIT_VALUES.
The LSB_JOBPEND environment variable is set if the job is requeued. If the
job’s execution environment could not be set up, LSB_JOBEXIT_STAT is set
to 0.
See “Automatic Job Requeue” on page 301 for more information.
◆ If both queue and job-level pre-execution commands are specified, the joblevel
pre-execution is run after the queue-level pre-execution command.
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Administering Platform LSF