Requests in flight dropped during "graceful" shutdown

[amcinnes]

gunicorn version: 20.0.4

Expected behaviour: after receiving SIGTERM, gunicorn should not accept any new connections, but should finish handling requests on existing connections (and respond with Connection: close so the client knows not to send another request)

Actual behaviour: In some situations, during a graceful shutdown gunicorn terminates a connection where a request has already been received, without processing the request.

To reproduce:

1. Put this in app.py (it's an example copied from the docs, but with time.sleep(10) added to it):

import time

def app(environ, start_response):
    """Simplest possible application object"""
    data = b'Hello, World!\n'
    status = '200 OK'
    response_headers = [
        ('Content-type', 'text/plain'),
        ('Content-Length', str(len(data)))
    ]
    time.sleep(10)
    start_response(status, response_headers)
    return iter([data])

2. Run gunicorn app:app

3. In two other terminals, run curl localhost:8000

4. Before the curl commands have finished, send SIGTERM to the master gunicorn process

You will see that one of the curl commands succeeds, and the other one gives an error "Connection reset by peer".

[benoitc]

On which system?

On Fri 26 Feb 2021 at 08:57, Angus McInnes ***@***.***> wrote: *gunicorn version:* 20.0.4 *Expected behaviour:* after receiving SIGTERM, gunicorn should not accept any new connections, but should finish handling requests on existing connections (and respond with Connection: close so the client knows not to send another request) *Actual behaviour:* In some situations, during a graceful shutdown gunicorn terminates a connection where a request has already been received, without processing the request. *To reproduce:* 1. Put this in app.py (it's an example copied from the docs, but with time.sleep(10) added to it): import time def app(environ, start_response): """Simplest possible application object""" data = b'Hello, World!\n' status = '200 OK' response_headers = [ ('Content-type', 'text/plain'), ('Content-Length', str(len(data))) ] time.sleep(10) start_response(status, response_headers) return iter([data]) 1. Run gunicorn app:app 2. In two other terminals, run curl localhost:8000 3. Before the curl commands have finished, send SIGTERM to the master gunicorn process You will see that one of the curl commands succeeds, and the other one gives an error "Connection reset by peer". — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2529>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAADRIR4PBREANBQJD3KOVTTA5H67ANCNFSM4YH7IPLQ> .

-- Sent from my Mobile

[amcinnes]

On Linux.

[tilgovi]

Tracking this over in #1236. If you're using the threaded worker or the eventlet worker, this is a known issue. If not, can you please let us know what worker class you're using and we can keep this open to track that?

[benoitc]

old issue without any activity. closing it. feel free to open a new ticket if needed.