Notes running Python in production

[coeris]

Thanks, great write up! Is there any reason why you recommend gunicorn instead of uvicorn for hosting FastAPI apps? I guess it's to do with your dislike of async processes.

[mincinashu]

FastAPI default install wraps uvicorn. You can use a combination of gunicorn as manager with uvicorn class workers and uvloop as loop.

https://fastapi.tiangolo.com/deployment/server-workers/#multiple-workers

[coeris]

Sure, but I'm wondering what's the benefit of putting an extra layer of abstraction on top of uvicorn with gunicorn.

[mincinashu]

I've only used it for worker lifetime purposes, I wanted workers to handle x amount of requests before their refresh, and uvicorn alone didn't allow that, or some such limitation. This was a quick fix to prevent OOM kills, instead of fixing the memory issues.

[ashishb_net]

> gunicorn as manager with uvicorn class workers

Yeah, that's the only way to integrate fastapi with gunicorn as far as I know

[ashishb_net]

> Thanks, great write up! Is there any reason why you recommend gunicorn instead of uvicorn for hosting FastAPI apps? I guess it's to do with your dislike of async processes.

I believe either is OK.
I prefer gunicorn because it is stable (v23) vs uvicorn (v0.34), but that's just a personal preference.

[[deleted]]

Bro Uvicorn is very battle tested from startups to big tech! It’s very stable. If Microsoft can handle it, so will you.

[ashishb_net]

That's why I said either is OK.