Demonstrating that Gunicorn does not respond immediately to SIGTERM (with Python 3.5)

console-log-14.04.txt

The script run-and-stop-gunicorn.sh takes 1 second on both Python 2.7 and 3.4.

$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.2 LTS"
$ 
$ 
$ source 27-env/bin/activate
(27-env)$ time ./run-and-stop-gunicorn.sh 
[2016-05-09 17:07:16 +0000] [2735] [INFO] Starting gunicorn 19.4.5
[2016-05-09 17:07:16 +0000] [2735] [INFO] Listening at: http://127.0.0.1:8000 (2735)
[2016-05-09 17:07:16 +0000] [2735] [INFO] Using worker: sync
[2016-05-09 17:07:16 +0000] [2741] [INFO] Booting worker with pid: 2741
[2016-05-09 17:07:17 +0000] [2735] [INFO] Handling signal: term
[2016-05-09 17:07:17 +0000] [2741] [INFO] Worker exiting (pid: 2741)
[2016-05-09 17:07:17 +0000] [2735] [INFO] Shutting down: Master

real	0m1.043s
user	0m0.137s
sys	0m0.041s
(27-env)$ deactivate
$ 
$ 
$ source 34-env/bin/activate
(34-env)$ time ./run-and-stop-gunicorn.sh 
[2016-05-09 17:07:31 +0000] [2763] [INFO] Starting gunicorn 19.4.5
[2016-05-09 17:07:31 +0000] [2763] [INFO] Listening at: http://127.0.0.1:8000 (2763)
[2016-05-09 17:07:31 +0000] [2763] [INFO] Using worker: sync
[2016-05-09 17:07:31 +0000] [2767] [INFO] Booting worker with pid: 2767
[2016-05-09 17:07:32 +0000] [2763] [INFO] Handling signal: term
[2016-05-09 17:07:32 +0000] [2767] [INFO] Worker exiting (pid: 2767)
[2016-05-09 17:07:32 +0000] [2763] [INFO] Shutting down: Master

real	0m1.096s
user	0m0.281s
sys	0m0.027s
(34-env)$ deactivate

console-log-16.04.txt

Bash session output. Notice that the script run-and-stop-gunicorn.sh
takes 1 second on Python 2.7, but takes 30 seconds on Python 3.5.


$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04 LTS"
$ 
$ 
$ source 27-env/bin/activate
(27-env) $ python --version
Python 2.7.11+
(27-env) $ gunicorn --version
gunicorn (version 19.4.5)
(27-env) $ time ./run-and-stop-gunicorn.sh 
[2016-05-09 22:32:41 +0000] [12724] [INFO] Starting gunicorn 19.4.5
[2016-05-09 22:32:41 +0000] [12724] [INFO] Listening at: http://127.0.0.1:8000 (12724)
[2016-05-09 22:32:41 +0000] [12724] [INFO] Using worker: sync
[2016-05-09 22:32:41 +0000] [12730] [INFO] Booting worker with pid: 12730
[2016-05-09 22:32:42 +0000] [12724] [INFO] Handling signal: term
[2016-05-09 22:32:42 +0000] [12730] [INFO] Worker exiting (pid: 12730)
[2016-05-09 22:32:42 +0000] [12724] [INFO] Shutting down: Master

real	0m1.040s
user	0m0.200s
sys	0m0.020s
(27-env) $ deactivate 
$ 
$ 
$ source 35-env/bin/activate
(35-env) $ python --version
Python 3.5.1+
(35-env) $ gunicorn --version
gunicorn (version 19.4.5)
(35-env) $ time ./run-and-stop-gunicorn.sh 
[2016-05-09 22:33:20 +0530] [12758] [INFO] Starting gunicorn 19.4.5
[2016-05-09 22:33:20 +0530] [12758] [INFO] Listening at: http://127.0.0.1:8000 (12758)
[2016-05-09 22:33:20 +0530] [12758] [INFO] Using worker: sync
[2016-05-09 22:33:20 +0530] [12762] [INFO] Booting worker with pid: 12762
[2016-05-09 22:33:21 +0530] [12758] [INFO] Handling signal: term
[2016-05-09 22:33:51 +0530] [12758] [INFO] Shutting down: Master

real	0m31.104s
user	0m0.280s
sys	0m0.028s
(35-env) $ deactivate
$ 

myapp.py

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)))
    ]
    start_response(status, response_headers)
    return iter([data])

run-and-stop-gunicorn.sh

#!/usr/bin/env bash

gunicorn --timeout 600 --pid gunicorn.pid myapp:app &
sleep 1
kill -TERM `cat gunicorn.pid`
wait