deRSE'25 Julia tutorial

This repository contains material for the Performance portability and high-performance computing with Julia workshop at the 5th conference for Research Software Engineering in Germany (deRSE25).

To find prerendered notebooks go to https://juliahpc.github.io/deRSE25-workshop/.

Requirements

For the tutorials we will use Pluto.jl notebooks in Julia.

Installing Julia

Download and install Julia for your platform from here.

Installing Pluto.jl

Start Julia

$ julia
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.11.3 (2025-01-21)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

and run the following commands to install Pluto.jl:

] add Pluto

Start Pluto.jl

import Pluto
Pluto.run()

Load the notebooks from this repository. Alternatively, you can view a prerendered static html version of the notebooks (see above).

Other options for running the notebooks without installing Julia on your machine

Using a Docker container

We also provide a Docker image (built for linux/amd64 and linux/arm64) for running the notebook, which you can pull with

docker pull ghcr.io/juliahpc/derse25-workshop:main

Pluto can then be run on MacOS or Linux with

docker run -p 1234:1234 -ti ghcr.io/juliahpc/derse25-workshop:main julia -e 'using Pluto; Pluto.run(; host="0.0.0.0", port=1234)'

or if using PowerShell on Windows with

docker run -p 1234:1234 -ti ghcr.io/juliahpc/derse25-workshop:main julia -e 'using Pluto; Pluto.run(; host=""""0.0.0.0"""", port=1234)'

This will launch Pluto within the container, and if successful you should see a message similar to

[ Info: Loading...
┌ Info:
└ Go to http://0.0.0.0:1234/?secret=hgY7as1X in your browser to start writing ~ have fun!

where hgY7as1X in the URL will be replaced with another random alphanumeric string. The Pluto notebook environment is accessed as a web app, so you should open a browser window and navigate to the URL indicated in the message to open the Pluto interface. If you get Unable to connect message or similar when trying to open the URL, you may need to replace the 0.0.0.0 component with localhost, so for the example above you would navigate to http://localhost:1234/?secret=hgY7as1X.

Once you have the Pluto interface open in your browser, you can load the notebooks saved under /root. To open a notebook, find the Open a notebook section in the Pluto interface, click on the Enter path or URL... field and select root/ and then choose to the desidered notebook from the drop-down file navigator and finally click the Open button to open it.

GitHub Codespaces

[!NOTE] GitHub Codespaces is a convenient environment for running notebooks on the web for free, but the resources on the free plan are limited, and parallel scaling efficiency may be be poor in some cases.

You can also take advantage of the ability of GitHub Codespaces to run custom web apps. Go go the Codespaces page of this repository, click on the green button on the top right "Create codespace on main" and wait a few seconds for the codespace to start. In the bottom panel, go to the "Terminal" tab (other tabs should be "Problems", "Output", "Debug console", "Ports") and when you see the message (this can take a few seconds to appear after the codespace started, hold on)

[ Info: Loading...
┌ Info:
└ Go to http://localhost:1234/ in your browser to start writing ~ have fun!

go to the "Ports" tab, right click on the "Pluto server (1234)" port and click on "Open in browser" (alternatively, click on the globe-shaped button under the "Forwarded Addresses" column). This will open the Pluto landing page in a new tab in your browser and from there you can open the desired notebooks.

If you want to make your app accessible to others (please remember to make sure there's no sensitive or private data in it!), navigate to the "Ports" tab, right click on the "Pluto server (1234)" port and then "Port visibility" -> "Public".

The .devcontainer used here has been adapted from the Julia workshop for the UCL Festival of Digital Research & Scholarship 2024, in turn based on the Zero-setup R workshops with GitHub Codespaces repository presented at rstudio::conf 2022.

Further resources

If you have further questions about the use of Julia, especially in HPC setting, check out

• the Julia Discourse web forum for asking questions
• the Julia on HPC clusters notes

Everyone is also welcome to join the fortnightly Julia HPC community calls, the 2nd Thursday (at a European-friendly time) and the 4th Tuesday (at an American-friendly time) of the month.