I have used nginx and gunicorn to host my website in two servers,

Both server have same versions of packages and website is successfully hosted,

But in one of my server gunicorn always gets timeout and I get error

[CRITICAL]Worker Timeout
Booting worker with pid
Worker cannot boot with pid

And after this I get 502 Badgateway error in webpage. I have to restart the gunicorn process to bring up website.

Following is the error log :

2014-02-16 14:29:53 [1267] [CRITICAL] WORKER TIMEOUT (pid:4994)
2014-02-16 14:29:53 [1267] [CRITICAL] WORKER TIMEOUT (pid:4994)   
2014-02-16 14:29:53 [22140] [INFO] Booting worker with pid: 22140

And I get continuos error like this,

2014-02-16 14:29:53 [22140] [DEBUG] Ignoring EPIPE
Ignoring EPIPE
2014-02-16 14:29:53 [22140] [DEBUG] Ignoring EPIPE
Ignoring EPIPE
2014-02-16 14:29:57 [22140] [DEBUG] Ignoring EPIPE
Ignoring EPIPE

And worker starts again,

2014-02-16 14:32:44 [1267] [CRITICAL] WORKER TIMEOUT (pid:4993)
2014-02-16 14:32:44 [1267] [CRITICAL] WORKER TIMEOUT (pid:4993)
2014-02-16 14:32:44 [22276] [INFO] Booting worker with pid: 22276

Again Ignoring EPIPE error and this continues until I restart the gunicorn. And when I am getting this error I get 504 gateway error from nginx

  • 1
    Can you provide more information, please? The command-line you're using to launch Gunicorn would be a good start.
    – supervacuo
    Dec 18, 2013 at 13:49
  • Trace the worker to see where it's getting stuck: strace -p <PID> -e trace=network -t Feb 5, 2014 at 18:36
  • What is the application you are running? You might want to increase the default timeout. Feb 17, 2014 at 6:58
  • Yes Burhan Khalid , for now I have increased proxy_read_timeout to 1200 in nginx and timeout to 3600 in gunicorn configuration. Hope this works
    – s.m
    Feb 17, 2014 at 9:56
  • @s.m - did it work?
    – iamkhush
    Apr 16, 2016 at 8:33

1 Answer 1


To fix this increase the timeout flag in Nginx,

In Nginx increase proxy_connect_timeout and proxy_read_timeout, you can add the following in nginx.conf file under the http directive. They default to 60s.

proxy_connect_timeout 300s;

proxy_read_timeout 300s;

Restart Nginx server. See nginx docs on timeouts.

If above fix doesn't work, then increase Gunicorn timeout flag in Gunicorn configuration, default Gunicorn timeout is 30 seconds.

--timeout 90

Gunicorn documentation about timeout

-t INT, --timeout INT 30 Workers silent for more than this many seconds are killed and restarted.

Generally set to thirty seconds. Only set this noticeably higher if you’re sure of the repercussions for sync workers. For the non sync workers it just means that the worker process is still communicating and is not tied to the length of time required to handle a single request.

Gunicorn Docs on Worker Timeouts

Hope this solves it.

  • 2
    This solution saved my life after I was looking for a solution all day. If you genuinely have a process that runs longer than 30s (which was my problem), then this is definitely the correct solution. Mar 16, 2015 at 22:51
  • Yes, even we have a scenario that runs longer than 30 seconds, hence we adopted the solution. Nice it helped.
    – sreekanth
    Mar 17, 2015 at 12:14
  • We dont have such a scenario. There is a mininal traffic on site, but the workers timeout each day nearly at the same time. Then gets running after 1-2 mins. My setup is nginx - supervisor - gunicorn - django. I have timeout of 120 secs.
    – iamkhush
    Apr 15, 2016 at 9:55
  • 1
    proxy_connect_timeout: "Defines a timeout for establishing a connection with a proxied server. It should be noted that this timeout cannot usually exceed 75 seconds."
    – deweydb
    Dec 6, 2017 at 23:45
  • @iamkhush were you able to figure out the fix for this? I'm also facing this issue even when my application is idle. Gunicorn workers timeout daily and none of the solutions like increasing the timeout seem to work. Nov 11, 2019 at 13:28

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