Uvicorn worker processes die on startup when PYTHONDONTWRITEBYTECODE=1

[winstxnhdw]

To reproduce:

export PYTHONDONTWRITEBYTECODE=1
uvicorn main:app --workers 2

I have tested this on Debian Bookworm. Might want to make sure you do not have any *.pyc files as well.

[Kludex]

@abersheeran Do you know something about this?

[abersheeran]

This problem has never occurred in our environment. We have always run uvicorn/zibai in the docker container with PYTHONDONTWRITEBYTECODE=1.

[winstxnhdw]

It’s possible that you aren’t docker ignoring your *.pyc file which is copied over into the container.

[abersheeran]

Can you provide more information? For example, Traceback

[winstxnhdw]

I would provide a traceback if there was any but all I get is “Child process has died.” I’ll create a minimal example in a bit.

[abersheeran]

I recommend checking your code first to see if there is anything that would cause the process to exit. As far as I know, Uvicorn does not check pyc

[winstxnhdw]

False alarm. I had pyannote.audio imported in one of the script that I forgot to comment out. This causes Uvicorn workers to die for whatever reason. Why this only happens when workers are set to 2 and PYTHONDONTWRITEBYTECODE=1 is a mystery, but at least it's not Uvicorn's problem.

[winstxnhdw]

FWIW, I just migrated over to Granian with workers today, and it doesn't have this problem. It's likely that Uvicorn is hitting some edge case here.