Simple Linux Utility for Resource Management (SLURM)
SLURM is an open-source workload manager designed for Linux clusters of all sizes. It provides three key functions. First, it allocates exclusive or non-exclusive access to resources (computer nodes) to users for some duration of time so they can perform work. Second, it provides a framework for starting, executing, and monitoring work (typically a parallel job) on a set of allocated nodes. Finally, it arbitrates contention for resources by managing a queue of pending work.
- Submitting Jobs
- Checking Job Status
- Checking Cluster Status
- Understanding Job Priority
- Official Documentation
Below are some of the common commands used in SLURM. Further information on how to use these commands is found in the documentation linked above. To see all flags available for a command, please check the command's manual by using
man $COMMAND on the command line.
srun runs a parallel job on a cluster managed by SLURM. If necessary, it will first create a resource allocation in which to run the parallel job.
salloc allocates a SLURM job allocation, which is a set of resources (nodes), possibly with some set of constraints (e.g. number of processors per node). When salloc successfully obtains the requested allocation, it then runs the command specified by the user. Finally, when the user specified command is complete, salloc relinquishes the job allocation. If no command is specified, salloc runs the user's default shell.
sbatch submits a batch script to SLURM. The batch script may be given to sbatch through a file name on the command line, or if no file name is specified, sbatch will read in a script from standard input. The batch script may contain options preceded with "#SBATCH" before any executable commands in the script.
squeue views job and job step information for jobs managed by SLURM.
scancel signals or cancels jobs, job arrays, or job steps. An arbitrary number of jobs or job steps may be signaled using job specification filters or a space separated list of specific job and/or job step IDs.
sacct displays job accounting data stored in the job accounting log file or SLURM database in a variety of forms for your analysis. The sacct command displays information on jobs, job steps, status, and exitcodes by default. You can tailor the output with the use of the --format= option to specify the fields to be shown.
sstat displays job status information for your analysis. The sstat command displays information pertaining to CPU, Task, Node, Resident Set Size (RSS) and Virtual Memory (VM). You can tailor the output with the use of the --fields= option to specify the fields to be shown.
If you are trying to use GNU Modules in a Slurm job, please read the section of our Modules documentation on non-interactive shell sessions. This also needs to be done if the OS version of the compute node you are scheduled on is different from the OS version of the submission node you are submitting the job from.
Running Jupyter Notebook on a Compute Node
The steps to run a Jupyter Notebook from a compute node are listed below.
Setting up your Python Virtual Environment
Create a Python virtual environment on the compute node you are assigned and activate it. Next, install Jupyter using pip by following the steps here.
Running Jupyter Notebook
After you've set up the Python virtual environment, run the following command on the compute node you are assigned:
jupyter notebook --no-browser --port=8889 --ip=0.0.0.0
This will start running the notebook on port 8889. Note: You must keep this shell window open to be able to connect. If the submission node for the cluster you are using is not accessible via the public internet, you also must be on a machine connected to the UMIACS network or connected to our VPN in order to access the Jupyter notebook once you start the SSH tunnel, so ensure this is the case before starting the tunnel. Then, on your local machine, run
ssh -N -f -L localhost:8888:$(NODENAME):8889 $(USERNAME)@$(SUBMISSIONNODE).umiacs.umd.edu
This will tunnel port 8889 from the compute node to port 8888 on your local machine, using $(SUBMISSIONNODE) as an intermediate node. Make sure to replace $(USERNAME) with your username, $(SUBMISSIONNODE) with the name of the submission node you want to use, and $(NODENAME) with the name of the compute node you are assigned. For example, assuming your username is
username and that you are using the Nexus cluster, have been assigned the nexusgroup submission nodes, and are assigned compute node tron00.umiacs.umd.edu:
ssh -N -f -L localhost:8888:tron00.umiacs.umd.edu:8889 firstname.lastname@example.org
You can then open a web browser and type in
localhost:8888 to access the notebook.
- Later versions of Jupyter have token authentication enabled by default - you will need to prepend the
/?token=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXpart of the URL provided by the terminal output after starting the notebook in order to connect if this is the case. e.g.
- If the port on the compute node mentioned in the example above (8889) is not working, it may be that someone else has already started a notebook using that specific port number on that specific compute node. The port number can be replaced with any other ephemeral port number you'd like, just make sure to change it in both the command you run on the compute node and the ssh command from your local machine.
Quick Guide to translate PBS/Torque to SLURM
|Job submission||qsub [filename]||sbatch [filename]|
|Job deletion||qdel [job_id]||scancel [job_id]|
|Job status (by job)||qstat [job_id]||squeue --job [job_id]|
|Full job status (by job)||qstat -f [job_id]||scontrol show job [job_id]|
|Job status (by user)||qstat -u [username]||squeue --user=[username]|
|Job Name||-N [name]||--job-name=[name] OR -J [name]|
|Node Count||-l nodes=[count]||--nodes=[min[-max]] OR -N [min[-max]]|
|CPU Count||-l ppn=[count]||--ntasks-per-node=[count]|
|CPUs Per Task||--cpus-per-task=[count]|
|Memory Size||-l mem=[MB]||--mem=[MB] OR --mem-per-cpu=[MB]|
|Wall Clock Limit||-l walltime=[hh:mm:ss]||--time=[min] OR --time=[days-hh:mm:ss]|
|Node Properties||-l nodes=4:ppn=8:[property]||--constraint=[list]|
|Standard Output File||-o [file_name]||--output=[file_name] OR -o [file_name]|
|Standard Error File||-e [file_name]||--error=[file_name] OR -e [file_name]|
|Combine stdout/stderr||-j oe (both to stdout)||(Default if you don't specify --error)|
|Job Arrays||-t [array_spec]||--array=[array_spec] OR -a [array_spec]|
|Delay Job Start||-a [time]||--begin=[time]|