Running preexecution programs, Example 5-12 – HP XC System 3.x Software User Manual
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Example 5-12
Submitting a Batch job Script That Uses the srun --overcommit Option
$ bsub -n4 -I ./myscript.sh
Job <81> is submitted to default queue <normal>.
<<Waiting for dispatch ...>>
<<Starting on lsfhost.localdomain>>
n1
n1
n1
n1
n2
n2
n2
n2
Hello world! I'm 0 of 8 on n1
Hello world! I'm 1 of 8 on n1
Hello world! I'm 2 of 8 on n1
Hello world! I'm 3 of 8 on n1
Hello world! I'm 4 of 8 on n2
Hello world! I'm 5 of 8 on n2
Hello world! I'm 6 of 8 on n2
Hello world! I'm 7 of 8 on n2
shows some of the environment variables that are available in a batch script. The LSB_HOSTS
and LSB_MCPU_HOSTS environment variables are defined in
Platform LSF Reference. The SLURM_JOBID
and SLURM_NPROCS environment variables are defined in the
SLURM Reference Manual.
Example 5-13
Environment Variables Available in a Batch Job Script
$ cat ./envscript.sh
#!/bin/sh
name=`hostname`
echo "hostname = $name"
echo "LSB_HOSTS = '$LSB_HOSTS'"
echo "LSB_MCPU_HOSTS = '$LSB_MCPU_HOSTS'"
echo "SLURM_JOBID = $SLURM_JOBID"
echo "SLURM_NPROCS = $SLURM_NPROCS"
$ bsub -n4 -I ./envscript.sh
Job <82> is submitted to default queue <normal>.
<<Waiting for dispatch ...>>
<<Starting on lsfhost.localdomain>>
hostname = n1
LSB_HOSTS = 'n1 n1 n2 n2'
LSB_MCPU_HOSTS = 'n1 2 n2 2'
SLURM_JOBID = 176
SLURM_NPROCS = 4
Running Preexecution Programs
A
preexecution program is a program that performs needed setup tasks that an application needs. It may
create directories, input files, and so on.
Though LSF-HPC daemons only run on a node with resource manager role, batch jobs can run on any
compute node that satisfies the scheduling and allocation requirements.
Where preexecution commands run depends on the type of job:
•
For interactive jobs, preexecution commands run on the node where the sbatchd daemon runs,
typically, the resource manager node.
•
For normal batch jobs, preexecution commands run on the first node of the SLURM allocation.
Before starting a preexecution program, LSF-HPC sets the SLURM_JOBID environment variable. To enable
srun
to launch pre-execution on the first allocated node and other allocated nodes, your preexecution
Running Preexecution Programs
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