Jupyterhub is a web-based interactive development environment for notebooks, code, and data - it is available for use in select courses. Its underlying technology allows students to develop code or notebooks online through a web interface hosted inside individual Linux containers in a Kubernetes cluster. The Department has deployed a centralized instance of Jupyterhub that is available through its web servers.

Please contact your instructor to obtain the Jupyterhub URL for your course. The URL’s can change between terms, or may be different for individual courses.

All data is erased from Jupyterhub at the end of every term. Students wanting to keep their data should download their files from Jupyterhub before the end of term. Data stored in COSI home directories remains available for as long as the student is a member of the Department.

Your server can remain running for up to 15 minutes after you log out so if you need to hard restart it for some reason (maybe you have some code running out of control):

• From the “File” menu, click the “Hub Control Panel” and press the “Stop my server” button.

• Wait approximately 30 seconds until the “Start my Server” button turns blue and press it. This will hard kill your session, stop any running processes and restart your server from scratch.

Please close your Notebooks when you are finished using them - this issue only affects Jupyter notebooks, and not general programming activity.

Each student has a limit on the amount of the maximum RAM and CPU available to them in Jupyterhub.

If you haven’t closed any of your old notebooks from past assignments, its possible as the term progresses that you can exceed your CPU/RAM quota when you next log in because all the notebooks you left open restart every time log in - crashing your log in session.

You can then manually reset your saved Jupyterlab workspace (what apps you have open), resetting your workspace back to the default launcher app open by appending /<username>/lab?resetto the Jupyterhub URL. If necessary, you may have to shutdown your server first (/hub/home/), and then use the reset URL to restart your server with a clean workspace.

When you launch an application from the launcher, the window closes and is replaced by your new application. If you want to open more applications in other tabs, click “File” > “New Launcher” to reload the launch panel in a new tab.

If you have opened multiple files, terminals or consoles from the “File” menu or the Launcher panel, each file or terminal will be opened in a separate overlapping tabbed panel. Tabbed panels can be dragged and dropped into different positions in the web browser by holding down the left-mouse button while dragging the “tab” of a panel into different corners of the browser. Releasing the left-mouse button will sub-divide the existing panel and make multiple panels visible at the same time.

Git repositories cannot be nested one inside another. If you accidentally created a git repository in the root of your home directory you won’t be able to create any new git repositories until you delete .git folder in your home directory.

The Jupyterhub file browser will only show files from your home directory. Files in the /home/shared_courses folder can be accessed at the command-line in a terminal, or directly from within your source code you write.