CODEWITHSUNDEEP
pythonjupyter-notebook
Thomas Mc Donald
Thomas Mc Donald

Reputation: 427

Chrome crashed, is jupyter notebook still running?

I am working on some very lengthy calculations (8 hours). While doing these calculations, I was working on something else in chrome. Something went wrong on that website, and chrome shut down, where also my jupyter notebook file was running. Now I have started it back up and the logo is still indicates the program is running (it shows the hourglass icon), but I am not sure if this is actually true, in that case I would like to restart the program as quickly as I can.

Hope you guys can help! Thanks!

Upvotes: 5

Views: 2964

Answers (1)

Norrius
Norrius

Reputation: 7920

I have just tested this on locally running Jupyter 4.4.0.

Cells submitted for running will complete as usual (assuming no exception occurs) as long as the kernel is still alive. After that computation is done, you can continue working on the notebook as usual. All changes to that kernel session are preserved, for example if you define a function or save your result in a variable, they will be available later. If you have it doing intensive computation, you can check your system monitor: python consuming lots of CPU means that it is probably still running.

If you have unsaved changes to your notebook, for example new code or cells, they will be lost. The code in them still seems to be executed though if it was set to run (Ctrl+Enter).

If you open localhost:8888 in a browser again, you should be able to see if the kernel is running (e.g. the hourglass icon). The running/idle detection seems to work fine upon reconnect.

However, the new browser session never gets updates from other sessions. This means that everything sent by the running code to the standard output (e.g. with print) after the disconnect is irretrievably lost, but you can still see what it printed before you got disconnected, assuming it was (auto-)saved. Once the kernel is done and you run cells from this new session, your browser will correctly get updates and display output as usual. Apparently (#641, #1150, #2833; thanks @unutbu) it is still not fixed due to Jupyter's architecture requiring a huge rework for that to function.

You can also attach a console with jupyter console --existing your-kernel-session-uuid, but it will not respond until the kernel is idle.

Upvotes: 6

Related Questions