Compute FAQ#

Quick answers for getting onto the hub at OHW26. For the full walkthrough with screenshots, see the JupyterHub preparation page.

What are we using for compute?#

CryoCloud — a community JupyterHub, run on 2i2c infrastructure, where we can set up pre-configured compute environments for the tutorials. We use it for tutorials and for project work.

The hub is at https://hub.cryointhecloud.com.

What do I need to do before I log in?#

Two things, both on GitHub:

  1. Accept the invitation to the OceanHackWeek GitHub organization, so that you show up in ohw26-participants.

  2. Make your organization membership public. Find yourself on the team page above, open your profile within the organization (a URL like https://github.com/orgs/oceanhackweek/people/YOUR-USERNAME), and check that Membership reads public rather than private.

CryoCloud works out what you can access from your GitHub team membership, so it can’t see you if your membership is private.

What happens the first time I log in?#

GitHub will ask you to authorize nasa-cryo-prod (the CryoCloud deployment, run by 2i2c) to read your organization and team membership.

Grant access to the oceanhackweek organization

On the authorization screen, make sure oceanhackweek is granted — if it shows an ✕ with a Grant button next to it, click Grant before you authorize.

Which environment and how much RAM should I pick?#

You choose both on the Server Options page, every time you start a server:

  • Environment — the OceanHackWeek Python Image for the tutorials and most project work. If you’re working in R, pick the Py-Rocket R image instead.

  • Resource Allocation — 8 GB of RAM should be enough for the tutorials. Pick the smallest allocation that does the job; the compute is shared and donated.

Why is it taking so long to start?#

Starting a new node and pulling our environment can take several minutes, especially when everyone logs in at once at the beginning of a tutorial. Be patient rather than reloading repeatedly.

How do I get the tutorials?#

Use the nbgitpuller link for the profile you’re running:

Pull the tutorials into JupyterLab

Pull the tutorials into RStudio

Clicking the link again later will pull in any updates and merge them with your own changes. See the extended discussion for the details, and for the git-based alternative.

What should I do when I’m finished for the day?#

Please shut down your server. Go to File > Hub Control Panel (or straight to https://hub.cryointhecloud.com/hub/home if you’ve closed the tab), then click Stop My Server.

File > Log Out does not shut the server down.

You will not lose your work

Stopping your server does not delete any of your files. It just releases the compute, like turning off your desktop at the end of the day.

Can I keep using CryoCloud after OceanHackWeek?#

Yes. Go through CryoCloud’s own getting started instructions, including the survey. You’ll be invited to their Slack channel, which is how the hub admins and users stay in touch.

Two notes on that form:

  • Award number — if you don’t have a grant number, enter OceanHackWeek. It doesn’t bill any grant; it’s used for tracking and for justifying their compute credits.

  • Institution — the list is a bit US-centric at the moment. If one of the options is a reasonable match but there’s a better term for your situation, put that down under Other, so the form can be improved.

Something’s broken and this page didn’t help#

Ask in the #ohw26_helpdesk Slack channel. See the Getting Help page for the other help groups.