KernelTerminated

Jupyter Kernel Terminated

This page is may be helpful if you see the message: "Kernel terminated -- this might be caused by running out of memory or hitting a bug in some library (e.g., forking too many processes, trying to access invalid memory, etc.). Consider restarting or upgrading your project or running the relevant code directly in a terminal to track down the cause."

Is it caused by using up too much memory?

Jupyter kernels terminating, and calculations failing that previously worked, can be a sign that your project is running low on memory.

Currently in CoCalc, if you open several Jupyter notebooks, they just sit there using memory. You have to explicitly kill them with top or click "Restart" or restart your project in order for them to go away. This can be a significant problem if you are grading a dozens of assignments.

See Is My Project Running Out of Memory for more information on how to detect and deal with low-memory situations.

Is it caused by something else?

It's possible, though by far the main source of trouble is lack of memory. If you suspect another problem, here are some thing to try:

1. Try to eliminate Jupyter if possible.

Open a terminal, type e.g., anaconda3, then copy and paste code in. Or put the code in a .py file, then import it. CoCalc is also very good for editing .py files directly. Does it segmentation fault or otherwise crash in a way that is very difficult for Jupyter to report? (Of course, if so, we want to know -- [email protected]).

2. Try to eliminate the CoCalc user interface.

Another thing you might try is to eliminate the CoCalc user interface to see what happens. Go to project settings and search for "Plain Jupyter Server", read the caveats, then click on that link. You'll probably have to refresh your browser once after clicking. Then navigate to your Jupyter notebook and open it. If everything always works fine here, but not in CoCalc, there is some issue specifically with the CoCalc interface. Let us know ([email protected]).