Find your way around by using it
EugoIDE is a JupyterLab environment in your browser. If you have used JupyterLab, most of it is familiar and you can skim. The new part is the cluster panel on the right.
Rather than describe the regions, this lesson has you touch each one. Five minutes, and the layout sticks in a way reading about it does not.
1. Save a file and prove it persists
Open a terminal from the launcher and write a file:
echo "written at $(date)" > ~/persistence-test.txt
cat ~/persistence-test.txt
Now write one somewhere else:
echo "also written" > /tmp/vanishes.txt
Look at the file browser on the left. persistence-test.txt is there; /tmp/vanishes.txt is not in
that tree.
That tree is the thing that survives. Close your session, come back tomorrow, and
persistence-test.txt is still there. /tmp/vanishes.txt is gone the moment the session ends.
If a file is not visible in the file browser, do not expect it to exist next time. Files and persistence covers exactly where the boundary sits.
2. Run cells out of order, on purpose
New notebook. Three cells:
x = 1
x = 99
print(x)
Run them top to bottom with Shift+Enter. You get 99.
Now click back into the first cell, run it again, then run the third cell. You get 1, from a
notebook that visibly reads x = 99 above it.
Look at the gutter numbers. They read something like [4] [2] [5]: execution order, not position.
That mismatch is the usual cause of "it worked a minute ago."
The fix, whenever state stops making sense: restart the kernel and run everything top to bottom. It is faster than reasoning about what is stale.
3. Find out where your terminal actually runs
In that terminal:
hostname
nproc
Note both. Later, when you run work on a cluster and print hostname from inside a task, you will get
a different machine.
The terminal runs in your session, not on the cluster. Nothing you type there executes on a compute node. That distinction saves real confusion once clusters are involved.
4. Open the cluster panel
The EugoHPC Manager is on the right. Open it and look, without launching anything yet.
That panel is the whole interface between the notebook you are writing and the machines that run it. Its own lesson covers driving it.
Shortcuts worth the muscle memory
Learn these four and you stop reaching for the mouse:
| Shortcut | Action |
|---|---|
Shift+Enter | Run cell, select next |
Esc then A / B | Insert cell above / below |
Esc then D D | Delete cell |
Ctrl+Shift+C | Command palette (everything else is in here) |
Clean up
rm ~/persistence-test.txt
What you now know
- Which tree persists, and which paths do not, verified rather than assumed.
- Why a notebook can produce a value its own code contradicts, and how to fix it in one step.
- That your terminal is the session, not the cluster.
Next: notebooks, files, and what persists draws the persistence boundary precisely, including where data belongs when a whole cluster needs to read it.
Video: A tour of EugoIDE (same material, with a transcript).