Restoring computation output after disconnect in Notebook

[hadim]

Following this discussion https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/jupyter/8hyGKoBY6O0/RyEDDyOZAQAJ, I'd like to open an issue to track down progress on this feature.

The idea would be to add the capability to restore output of a running kernel after client reconnection.

Feel free to ask me to move this issue in a more appropriate jupyter project if needed.

[rshpeley]

Hey Carreau. I noticed on the google forum you said the code would need a significant refactor, and MinRK said it involved storing outputs on the server. In my case I'm ok with losing the outputs during the disconnect. I just need to be able to reconnect the browser session to the kernel to get new outputs and to get at the data and code I've loaded. Kernel/Reconnect doesn't do it. I've also tried closing the tab and opening a new one from the Jupyter base page.

This is fairly important for me. I live in a rural area with a poor internet connection and my notebook takes about 8 hours to load. I'm pretty well guaranteed to have an interruption during that time.

[rshpeley]

Still looking into this. This is currently just a problem for me on Jupyter, but I'm more interested in getting it solved for JupyterHub. I'm planning to use it to instruct a class at the university and students losing access to their assignment work through a disrupted connection is not an option.

mosh have solved this problem on terminals and it seems to me that using mosh's SSP (State Synchronization Protocol) with Speculation adapted to Jupyter Notebook requirements would be the best solution to this problem (see the mosh paper).

If you want to hand this problem off to JupyterHub that's ok with me, but others may like to see a solution for Jupyter as well.

[minrk]

This isn't really a JupyterHub problem. It should be fixed in the notebook (specifically JupyterLab), hopefully before too long.

[post2web]

This feature would be great!

[manuelsh]

Loosing the output of a Jupyter notebook if you are not connected to the hosting computer is a problem, although you can do some hacks. Having the capacity of recovering it would be great.

Just a side note: Apache Zeppelin notebook with Python interpreter doesn't have this problem, as it handles disconnects or multiple connects during tasks executions transparently. But it has its own problems: it loses interactive output for a running cell after a disconnect, although when a task is done it eventually shows all its output.

[louismartin]

Is there any update on this issue?