Information about the batch system (SLURM)

For the old torque documentation, please see the old documentation.

Please confer /etc/slurm/README.

The documentation of Slurm can be found ​here.

Overview

Slurm offers interactive and batch jobs (scripts submitted into the system). The relevant commands are srun and sbatch. The srun command can be used to spawn processes (please do not use mpiexec), both from the frontend and from within a batch script. You can also get a shell on a node to work locally there (e.g. to compile your application natively for a special platform.

Remark about modules

By default, Slurm passes the environment from your job submission session directly to the execution environment. Please be aware of this when running jobs with srun or when submitting scripts with sbatch. This behavior can be controlled via the --export option. Please refer to the ​Slurm documentation to get more information about this.

In particular, when submitting job scripts, it is recommended to load the necessary modules within the script and submit the script from a clean environment.

An introductory example

Suppose you have an mpi executable named hello_mpi. There are three ways to start the binary.

From a shell on a node

First, start a shell on a node. You would like to run your mpi task on 4 machines with 2 tasks per machine:

niessen@deepl:src/mpi > srun --partition=sdv -N 4 -n 8 --pty /bin/bash -i
niessen@deeper-sdv04:/direct/homec/zdvex/niessen/src/mpi >

The environment is transported to the remote shell, no .profile, .bashrc, … are sourced (especially not the modules default from /etc/profile.d/modules.sh).

Once you get to the compute node, start your application using srun. Note that the number of tasks used is the same as specified in the initial srun command above (4 nodes with two tasks each):

niessen@deeper-sdv04:/direct/homec/zdvex/niessen/src/mpi > srun ./hello_cluster 
srun: cluster configuration lacks support for cpu binding
Hello world from process 6 of 8 on deeper-sdv07
Hello world from process 7 of 8 on deeper-sdv07
Hello world from process 3 of 8 on deeper-sdv05
Hello world from process 4 of 8 on deeper-sdv06
Hello world from process 0 of 8 on deeper-sdv04
Hello world from process 2 of 8 on deeper-sdv05
Hello world from process 5 of 8 on deeper-sdv06
Hello world from process 1 of 8 on deeper-sdv04

You can ignore the warning about the cpu binding. ParaStation will pin you processes.

Running directly from the front ends

You can run the application directly from the frontend, bypassing the shell:

niessen@deepl:src/mpi > srun --partition=sdv -N 4 -n 8 ./hello_cluster 
Hello world from process 4 of 8 on deeper-sdv06
Hello world from process 6 of 8 on deeper-sdv07
Hello world from process 3 of 8 on deeper-sdv05
Hello world from process 0 of 8 on deeper-sdv04
Hello world from process 2 of 8 on deeper-sdv05
Hello world from process 5 of 8 on deeper-sdv06
Hello world from process 7 of 8 on deeper-sdv07
Hello world from process 1 of 8 on deeper-sdv04

In this case, it can be useful to create an allocation which you can use for several runs of your job:

niessen@deepl:src/mpi > salloc --partition=sdv -N 4 -n 8 
salloc: Granted job allocation 955
niessen@deepl:~/src/mpi>srun ./hello_cluster 
Hello world from process 3 of 8 on deeper-sdv05
Hello world from process 1 of 8 on deeper-sdv04
Hello world from process 7 of 8 on deeper-sdv07
Hello world from process 5 of 8 on deeper-sdv06
Hello world from process 2 of 8 on deeper-sdv05
Hello world from process 0 of 8 on deeper-sdv04
Hello world from process 6 of 8 on deeper-sdv07
Hello world from process 4 of 8 on deeper-sdv06
niessen@deepl:~/src/mpi> # several more runs
...
niessen@deepl:~/src/mpi>exit
exit
salloc: Relinquishing job allocation 955

Batch script

Given the following script hello_cluster.sh: (it has to be executable):

#!/bin/bash

#SBATCH --partition=sdv
#SBATCH -N 4
#SBATCH -n 8
#SBATCH -o /homec/zdvex/niessen/src/mpi/hello_cluster-%j.log
#SBATCH -e /homec/zdvex/niessen/src/mpi/hello_cluster-%j.err
#SBATCH --time=00:10:00

srun ./hello_cluster

This script requests 4 nodes with 8 tasks, specifies the stdout and stderr files, and asks for 10 minutes of walltime. Submit:

niessen@deepl:src/mpi > sbatch ./hello_cluster.sh
Submitted batch job 956

Check what it's doing:

niessen@deepl:src/mpi > squeue
             JOBID PARTITION     NAME     USER ST       TIME  NODES NODELIST(REASON)
               956       sdv hello_cl  niessen  R       0:00      4 deeper-sdv[04-07]

Check the result:

niessen@deepl:src/mpi > cat hello_cluster-956.log 
Hello world from process 5 of 8 on deeper-sdv06
Hello world from process 1 of 8 on deeper-sdv04
Hello world from process 7 of 8 on deeper-sdv07
Hello world from process 3 of 8 on deeper-sdv05
Hello world from process 0 of 8 on deeper-sdv04
Hello world from process 2 of 8 on deeper-sdv05
Hello world from process 4 of 8 on deeper-sdv06
Hello world from process 6 of 8 on deeper-sdv07

Available Partitions

Please note that there is no default partition configured. In order to run a job, you have to specify one of the following partitions, using the --partition=... switch:

• sdv: The DEEP-ER sdv nodes
• knl: The DEEP-ER knl nodes (all of them, regardless of cpu and configuration)
• knl256: the 256-core knls
• knl272: the 272-core knls
• snc4: the knls configured in SNC-4 mode
• knm: The DEEP-ER knm nodes
• ml-gpu: the machine learning nodes equipped with 4 Nvidia Tesla V100 GPUs each
• extoll: the sdv and knl nodes in the extoll fabric

Anytime, you can list the state of the partitions with the sinfo command. The properties of a partition can be seen using

scontrol show partition <partition>

Interactive Jobs

Batch Jobs

FAQ

Why's my job not running?

You can check the state of your job with

scontrol show job <job id>

In the output, look for the Reason field.

You can check the existing reservations using

scontrol show res

How can I check which jobs are running in the machine?

Please use the squeue command.

How do I do chain jobs with dependencies?

Please confer the sbatch/srun man page, especially the

-d, --dependency=<dependency_list>

entry.

How can get a list of broken nodes?

The command to use is

sinfo -Rl -h -o "%n %12U %19H %6t %E" | sort -u

See also the translation table below.

Can I join stderr and stdout like it was done with -joe in Torque?

Not directly. In your batch script, redirect stdout and stderr to the same file:

...
#SBATCH -o /point/to/the/common/logfile-%j.log
#SBATCH -e /point/to/the/common/logfile-%j.log
...

(The %j will place the job id in the output file). N.B. It might be more efficient to redirect the output of your script's commands to a dedicated file.

What's the equivalent of qsub -l nodes=x:ppn=y:cluster+n_b:ppn=p_b:booster?

As of version 17.11 of Slurm, heterogeneous jobs are supported. For example, the user can run:

srun --partition=sdv -N 1 -n 1 hostname : --partition=knl -N 1 -n 1 hostname
deeper-sdv01
knl05

In order to submit a heterogeneous job, the user needs to set the batch script similarly to the following:

#!/bin/bash

#SBATCH --job-name=imb_execute_1
#SBATCH --account=deep
#SBATCH --mail-user=
#SBATCH --mail-type=ALL
#SBATCH --output=job.out
#SBATCH --error=job.err
#SBATCH --time=00:02:00

#SBATCH --partition=sdv
#SBATCH --constraint=
#SBATCH --nodes=1
#SBATCH --ntasks=12
#SBATCH --ntasks-per-node=12
#SBATCH --cpus-per-task=1

#SBATCH packjob

#SBATCH --partition=knl
#SBATCH --constraint=
#SBATCH --nodes=1
#SBATCH --ntasks=12
#SBATCH --ntasks-per-node=12
#SBATCH --cpus-per-task=1

srun ./app_sdv : ./app_knl

Here the packjob keyword allows to define Slurm parameter for each sub-job of the heterogeneous job.

If you need to load modules before launching the application, it's suggested to create wrapper scripts around the applications, and submit such scripts with srun, like this:

...
srun ./script_sdv.sh : ./script_knl.sh

where a script should contain:

#!/bin/bash

module load ...
./app_sdv

This way it will also be possible to load different modules on the different partitions used in the heterogeneous job.

pbs/slurm dictionary

PBS command	closest slurm equivalent
qsub	sbatch
qsub -I	salloc + srun —pty bash -i
qsub into an existing reservation	… —reservation= <reservation> …
pbsnodes	scontrol show node
pbsnodes (-ln)	sinfo (-R) or sinfo -Rl -h -o "%n %12U %19H %6t %E" | sort -u
pbsnodes -c -N n <node>	scontrol update NodeName?= <node> State=RESUME
pbsnodes -o <node>	scontrol update NodeName?= <node> State=DRAIN reason="some comment here"
pbstop	smap
qstat	squeue
checkjob <job>	scontrol show job <job>
checkjob -v <job>	scontrol show -d job <job>
showres	scontrol show res
setres	scontrol create reservation [ReservationName?= <reservation>] user=partec Nodes=j3c![053-056] StartTime?=now duration=Unlimited Flags=IGNORE_JOBS
setres -u <user> ALL	scontrol create reservation ReservationName?=\<some name> user=\<user> Nodes=ALL startTime=now duration=unlimited FLAGS=maint,ignore_jobs
releaseres	scontrol delete ReservationName?= <reservation>