gunicorn 19.9.0 async with eventlet not work?

[gangm]

I use gunicorn 19.9.0 + flask to test app:
app.py:

from flask import Flask
import time
app = Flask(__name__)

@app.route('/')
def index():
    print("in")
    for i in range(10):
        time.sleep(1)
    print("out")
    return 'hello world'

if __name__ == '__main__':
    app.debug = True
    app.run()

and boot cmd:
gunicorn -k eventlet -w 1 app:app --log-level=debug

test cmd:
curl localhost:8000

I think app can process multi requests at one time, but the test result is that app can only process 1 request at one time, and block in time.sleep()!

Is that gunicorn 19.9.0 can not work as async mode?

I attempted to use gunicorn 20.0.0, and there is no problem with async mode, but another problem occurs, --> #1559.
Now i have no idea which to use, gunicorn 19.9.0 or 20.0.0 ? (in our project, we use eventlet)

[jamadden]

eventlet is not monkey-patched in gunicorn 19.8 and 19.9; that's issue #1847 and was also pointed out in this thread. gunicorn 20 has an issue with sendfile using both gevent and eventlet that affects some people serving static content; that's been fixed in master.

Depending on your situation, there are a number of options. You could try using a different worker, for example gevent. Or you could try using a different gunicorn version, even potentially master. You could also try doing the monkey-patching yourself as described in #1559.

[averes-avidid]

Glad to know the static file thing has been fixed. This drove me crazy trying to figure out what was causing this. Well now I know why we should specify our versions in Pipfile/requirements.txt. When will this fix be pushed to PyPI?

[tilgovi]

Milestone for 20.0.1 here: https://github.com/benoitc/gunicorn/milestone/18

[benoitc]

@tilgovi @jamadden i has this feature been merged in 19.x also?

[tilgovi]

20.0.2 is released.

[tilgovi]

Also merged into 19.x as 253bfa1 and is in the 19.10 release.