Autosave does not checkpoint notebook

williambrandler commented 1 month ago

Description

We have a cloud environment where users can access a jupyterlab machine and write code in notebooks. Occasionally users get connection errors and are then told their File Changed and they are asked to Cancel / Revert / Overwrite (see screenshot)

A user clicked 'revert' and their notebook reverted back a few days. However, during this time their notebook had been saved many times using the autosave feature. It appears that the autosave is not also checkpointing the notebook, which is why the reversion went back many days to the last time the user explicitly saved the notebook. This means the user lost days of work

In summary:

If you click File -> Save Notebook, the notebook will save and checkpoint
If you rely on the autosave feature, the notebook will save but will not be checkpointed

I replicated the autosave checkpoint issue on a new machine in our cloud environment (no packages installed) and in classic Jupyter Notebook on my local machine (MacBook)

Is this expected behavior?

Reproduce

Create notebook "hello_world.ipynb"
Edit it and wait for autosave
go to terminal and check the time stamp for the checkpoint and for the notebook
- ls -l .ipynb_checkpoints
- ls -l hello_world.ipynb
Wait one minute and repeat steps 2 + 3
Now edit notebook again and click File -> Save Notebook
Repeat step 3

I diagnosed this in the original jupyterlab environment (docker container on a cloud virtual machine) and in Classic Jupyter Notebook on my local machine

Expected behavior

File checkpoints on autosave

Context

Browser and version: Chrome 128
JupyterLab version: 4.2.2

Selected Jupyter core packages... IPython : 8.25.0 ipykernel : 6.29.4 ipywidgets : 8.1.3 jupyter_client : 8.6.2 jupyter_core : 5.7.2 jupyter_server : 2.14.1 jupyterlab : 4.2.2 nbclient : 0.10.0 nbconvert : 7.16.4 nbformat : 5.10.4 notebook : 7.2.1 qtconsole : not installed traitlets : 5.14.3

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JasonWeill commented 4 weeks ago

@williambrandler Thank you for opening this issue! It seems like a reasonable expectation that auto-save would also automatically create checkpoints. We might need to investigate where the autosave logic lives (in JupyterLab, Jupyter Server, or elsewhere).

williambrandler commented 4 weeks ago

ok great, yeah having autosave also checkpoint would be great to match the behavior of using File -> Save Notebook

in the end we were able to recover the user's work via the ipython history, although it does take a bit longer to reconstruct the lost code via the command history as opposed to using a much more recent checkpoint

ipython
IN [1]: %hist -o -g -f ipython_history.md

jupyterlab / jupyterlab