Using MATLAB on HPC
MATLAB uses a search path to locate files. You can explicitly set the search path using the MATLABPATH environment variable in your Slurm or environment setup script with a line like the following:
Within a script, use path to display MATLAB’s search path, and addpath() to add a new location to the search path.
>> path >> addpath('/home/rcf-proj/tt/ttrojan/matlab') >> path
Running MATLAB Interactively
It is a good idea to test your MATLAB program on an “interactive” compute node, before submitting a batch (remote) job. The following will request a compute node with 8 cpus, each with 2GB of memory, for 1 hour and, when the resource is allocated, log you into the node.
[ttrojan@hpc-login3]$ salloc --ntasks=8 --mem-per-cpu=2g --time=1:00:00 salloc: Pending job allocation 2377051 salloc: job 2377051 queued and waiting for resources salloc: job 2377051 has been allocated resources salloc: Granted job allocation 2377051 salloc: Waiting for resource configuration salloc: Nodes hpc3676 are ready for job ---------- Begin SLURM Prolog ---------- Job ID: 2377051 Username: ttrojan Accountname: lc_hpcc Name: sh Partition: quick Nodelist: hpc3676 TasksPerNode: 8 CPUsPerTask: Default TMPDIR: /tmp/2377051.quick SCRATCHDIR: /staging/scratch/2377051 Cluster: uschpc HSDA Account: false ---------- 2018-12-12 17:59:36 --------- [ttrojan@hpc3676]$
Once you are on a compute node, select the version of MATLAB you wish to run from /usr/usc/matlab. Now load, or “source” the setup script for your selected version to configure your current environment to find and use that version of MATLAB.
$ source /usr/usc/matlab/R2018a/setup.sh
Note: This assumes you are running in a bash shell. For a (t)csh shell, source setup.csh.
To test an example, create a test file, hello.m and add the following lines:
disp('Hello Tommy!') exit
You can use the option –nodisplay to suppress the graphical interface. Batch jobs run remotely with no GUI. Note: You cannot suppress the copyright.
$ matlab -nodisplay -r hello < M A T L A B (R) > Copyright 1984-2018 The MathWorks, Inc. R2018a (188.8.131.523654) 64-bit (glnxa64) February 23, 2018 : Hello Tommy!
Alternatively, you can run your program within MATLAB.
[ttrojan@hpc-login3]$ matlab -nodisplay < M A T L A B (R) > Copyright 1984-2018 The MathWorks, Inc. R2018a (184.108.40.2063654) 64-bit (glnxa64) February 23, 2018 : # If code in same directory where MATLAB was invoked >> hello Hello Tommy! # If not, add its path to MATLAB's search path >> addpath('/home/rcf-proj/tt/ttrojan/matlab/hello') Hello Tommy!
Running MATLAB Remotely
When you have tested your MATLAB program and are ready to run it remotely, i.e., in batch mode, you will create a new text file, called a job script, where you will specify the compute resources and commands needed to run your job. The following job script, myjob.slurm, will request 16 cpus on a single compute node, each with 2GB of memory, for 4 hours, and will then set up MATLAB R2018a and run myprogram.m.
#!/bin/bash #SBATCH --ntasks=1 #SBATCH --cpus-per-task=16 #SBATCH --mem-per-cpu=2GB #SBATCH --time=4:00:00 #SBATCH --export=none #Ensures job gets a fresh login environment source /usr/usc/matlab/R2018a/setup.sh matlab -nodisplay -r hello
You can now submit your job for remote processing using Slurm’s sbatch jobscript command.
[ttrojan@hpc-login3 matlab]$ sbatch example_matlab.slurm Submitted batch job 1131075
To check on the status of your job use the command squeue -u username. If you are on a head node, you can use the HPC squeue wrapper myqueue.
$ squeue -u ttrojan JOBID PARTITION NAME USER ST TIME NODES NODELIST(REASON) 1131095 quick example_matlab ttrojan PD 0:00 2 (Resources) $ myqueue JOBID USER ACCOUNT PARTITION NAME TASKS CPUS_PER_TASK MIN_MEMORY START_TIME TIME TIME_LIMIT STATE NODELIST(REASON) 1131075 ttrojan lc_tt1 quick example_matlab 16 1 1G 2018-07-02T11:14:46 1:49 30:00 RUNNING hpc1046
By default, all output sent to the console, including error messages and print statements, is directed to a file named “slurm-%j.out”, where the “%j” is replaced with the job ID number. The file will be generated on the first node of the job allocation.
Any files created by the MATLAB program itself will be created as specified by the program.
Running MATLAB Graphically
MATLAB can be run graphically, as you would run it on your personal computer. You must log in to a head node with X11 Forwarding enabled.
ssh -X email@example.com
This documentation gives only a brief description. The process is explained in detail in the Parallel MATLAB on HPC presentation.
To run MATLAB graphically, type the following. The ‘&’ runs the program in the background.
$ source /usr/usc/matlab/R2018a/setup.sh $ matlab &
USC has a university-wide license for MATLAB that includes the Linux versions maintained by USC in /usr/usc/matlab. Additionally, HPC licenses MATLAB’s Parallel Computing Toolbox and MATLAB Distributed Computing Server for running single and multi node parallel jobs.
The following command displays the number of MATLAB licenses that are in use:
$ /usr/usc/matlab/R2016a/etc/glnxa64/lmutil lmstat -a -c /usr/usc/matlab/R2016a/licenses/network.lic | grep MATLAB Users of MATLAB: (Total of 10000 licenses issued; Total of 16 licenses in use) "MATLAB" v39, vendor: MLM, expiry: 30-jan-2019 Users of MATLAB_Distrib_Comp_Engine: (Total of 1000 licenses issued; Total of 376 licenses in use) "MATLAB_Distrib_Comp_Engine" v39, vendor: MLM, expiry: 01-jan-0000
You can search for the MATLAB distributed computing licenses that are checked out to you:
$ /usr/usc/matlab/R2016a/etc/glnxa64/lmutil lmstat -a -c /usr/usc/matlab/R2016a/licenses/network.lic | grep -e MATLAB -e Distrib_Comp -e ttrojan Users of MATLAB: (Total of 10000 licenses issued; Total of 14 licenses in use) "MATLAB" v39, vendor: MLM, expiry: 30-jan-2019 ttrojan hpc3613 /dev/tty (v36) (hpc-licenses/28518 121423), start Thu 12/20 16:09 Users of Distrib_Computing_Toolbox: (Total of 10000 licenses issued; Total of 12 licenses in use) "Distrib_Computing_Toolbox" v39, vendor: MLM, expiry: 30-jan-2019 ttrojan hpc3613 /dev/tty (v36) (hpc-licenses/28518 91467), start Thu 12/20 16:09 Users of MATLAB_Distrib_Comp_Engine: (Total of 1000 licenses issued; Total of 346 licenses in use) "MATLAB_Distrib_Comp_Engine" v39, vendor: MLM, expiry: 01-jan-0000 ttrojan hpc3617 /dev/tty (v36) (hpc-licenses/28518 3926), start Thu 12/20 10:02 ttrojan hpc3617 /dev/tty (v36) (hpc-licenses/28518 121423), start Thu 12/20 16:09 ttrojan hpc3615 /dev/tty (v36) (hpc-licenses/28518 61352), start Thu 12/20 10:03 ttrojan hpc3615 /dev/tty (v36) (hpc-licenses/28518 91467), start Thu 12/20 16:09
There are options for debugging MATLAB. See the matlab (Linux) page on the Mathworks website.