Julia

Julia was created as an open source alternative to MATLAB and Octave.

External Links:
Julia website
Learning Julia

Loading Julia

module avail julia

module load julia

module load julia/1.11.6

Running Julia

Do not use Julia on a login node. Submit Julia scripts with a batch submission file, and use the HPC-VCL if doing interactive visualization with Julia.

Batch Serial Julia Job

Here is an example batch script. For more information on submitting batch scripts, see the documentation on running jobs.

For a sample Julia script called my_code.jl containing

# a simple Julia code
using LinearAlgebra

a = [1,2,4];
println("a",a)
b = normalize(a)
println("normalize(a)",b)
println("norm(b)",norm(b))

and a sample submission script submit.sh

#!/bin/bash
#SBATCH --ntasks=1
#SBATCH --time=00:30:00
#SBATCH --output=out.%j
#SBATCH --error=err.%j

module load julia
julia my_code.jl

a batch job is submitted as

sbatch submit.sh

Script submit.sh requests the use of 1 core (--ntasks=1) for up to 30 minutes (--time=00:30:00). The output in out.JOBID is

a[1, 2, 4]
normalize(a)[0.2182178902359924, 0.4364357804719848, 0.8728715609439696]
norm(b)1.0

running jobs

Batch Shared Memory Parallelization (Multithreading) Julia Job

If your Julia script takes advantage of multithreading (i.e., using more than one core on just one node for parallelization), then you need to change your batch submission file accordingly.

Here is an example "Hello World" .jl script for multithreading called test_multithread.jl:

import Printf
N=4
Threads.@threads for i in 1:N
  sleep(1)
  Printf.@printf "Hello from thread %d\n" i
end

Here is a sample submission script submit.sh. It is important to note that shared memeory jobs can only be run with the latest version of Julia (1.12.6), which is the default version of Julia on the cluster.

#!/bin/bash
#SBATCH --ntasks=1
#SBATCH --cpus-per-task=4       
#SBATCH --time=00:30:00
#SBATCH --mem=20G               
#SBATCH --output=out.%j
#SBATCH --error=err.%j

module load julia
julia test_multithread.jl

The batch job is submitted as

sbatch submit.sh

Script submit.sh requests the use of 4 cores (--cpus-per-task=4) and 20 GB of RAM (--mem=20G) for up to 30 minutes (--time=00:30:00). The output in out.JOBID looks similar to (order of threads differs each time)

Hello from thread 1
Hello from thread 2
Hello from thread 4
Hello from thread 3

Batch Distributed Memory Parallelization (MPI) Julia Job

If your Julia script takes advantage of MPI (i.e., using multiple cores on multiple nodes for parallelization), then you need to change your batch submission file accordingly.

Here is an example "Hello World".jl script for MPI: example

Here is the submission script submit.sh for 04-sendrecv.jl. Similar to the shared memory jobs, it is important to note that distributed memory jobs can only be run with the latest version of Julia (1.12.6), which is the default version of Julia on the cluster.

#!/bin/bash
#SBATCH --ntasks=4
#SBATCH --cpus-per-task=1
#SBATCH --time=00:30:00
#SBATCH --output=out.%j
#SBATCH --error=err.%j

module load julia
srun julia 04-sendrecv.jl

A batch job is submitted as

sbatch submit.sh

and the output in out.JOBID looks similar to (order may be different, in fact, it may be different every time you run it)

Loading julia/1.12.6
  Loading requirement: openmpi-gcc/openmpi5.0.9-gcc11.5.0-slurm
1: Sending   1 -> 2 = [1.0, 1.0, 1.0, 1.0]
3: Sending   3 -> 0 = [3.0, 3.0, 3.0, 3.0]
0: Sending   0 -> 1 = [0.0, 0.0, 0.0, 0.0]
0: Received 3 -> 0 = [3.0, 3.0, 3.0, 3.0]
2: Sending   2 -> 3 = [2.0, 2.0, 2.0, 2.0]
3: Received 2 -> 3 = [2.0, 2.0, 2.0, 2.0]
2: Received 1 -> 2 = [1.0, 1.0, 1.0, 1.0]
1: Received 0 -> 1 = [0.0, 0.0, 0.0, 0.0]

running jobs

Installing Julia packages

Additional packages outside of the base Julia install must be installed by the user. See the instructions for request a space for user maintained software.

The basic process to install a new Julia package is to use Pkg.add from a login node. By default, Julia will install the packages in the home directory in ~/.julia. That will quickly fill the home directory. The Research Storage is a good option: OIT Research Storage

The generic path /path/to/pkgs will be used below as a placeholder below. Use the appropriate path you have access to.

Personal Research Storage

If you have your own research storage space, your path will be /rs1/researchers/<first_letter_of_your_username>/$USER/

PI's Research Storage

If you are a member of a PI's research group, your path will be /rs1/researchers/<first_letter_of_your_PI_username>/<PI_username>/

Before installing packages, set the location for the installs by setting JULIA_DEPOT_PATH to the user maintained software directory.

mkdir -p /path/to/pkgs/.julia
export JULIA_DEPOT_PATH=/path/to/pkgs/.julia

module load julia
julia
import Pkg
Pkg.add("whatever")

Check the Julia documentation on setting environment variables.

Last modified: September 01 2026 21:22:40.