--timeout-graceful-shutdown not behaving as expected

[ichernev]

I'm running this with latest 0.23.2 version, with the following code.

import asyncio
import json
import sys
from fastapi import FastAPI
from sse_starlette.sse import EventSourceResponse


app = FastAPI()

async def gen(n=10):
    try:
        for i in range(n):
            yield json.dumps({'i': i})
            await asyncio.sleep(1)
        yield 'DONE'
    except BaseException as e:
        import traceback
        traceback.print_exception(e)
        print("got ex", file=sys.stderr)
    finally:
        print("got fin", file=sys.stderr)


@app.get("/")
def read_root():
    return EventSourceResponse(gen())

I start with

uvicorn experiments.fastapi:app --host 0.0.0.0 --port 8001 --timeout-graceful-shutdown=10

And then I run

curl http://127.0.0.1:8001/

And when I ctrl-c the uvicorn my request is killed immediately, disregarding the graceful period.

The funny thing is that the killing of the generator happens even before the shutdown function starts:

INFO:     Started server process [2965347]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:8001 (Press CTRL+C to quit)
INFO:     127.0.0.1:54920 - "GET / HTTP/1.1" 200 OK
^CTraceback (most recent call last):
  File "/home/iskren/src/deepinfra/backend/experiments/fastapi.py", line 14, in gen
    await asyncio.sleep(1)
  File "/home/iskren/miniconda3/envs/di-main/lib/python3.10/asyncio/tasks.py", line 605, in sleep
    return await future
asyncio.exceptions.CancelledError
got ex
got fin
ERROR:    ASGI callable returned without completing response.
INFO:     Shutting down
INFO:     Waiting for application shutdown.
INFO:     Application shutdown complete.

Another funny thing is I can't really understand WHAT is causing the task to be cancelled. If I run a basic asyncio loop + handle signal and print inside the generators are not cancelled.

[sean1iu]

Has this been solved?

[krevedkin]

+1 to comment above. Has this been solved?