How to properly debug Gunicorn - WORKER TIMEOUT ?

Question

Django

An error began to appear in the Nginx logs
upstream timed out (110: Connection timed out)
. That is, nginx does not receive a response from the proxy server (Gunicorn), in the Gunicorn logs there is this:

2014-12-11 18:11:33 [928] [CRITICAL] WORKER TIMEOUT (pid:4381)
2014-12-11 18:11:59 [928] [CRITICAL] WORKER TIMEOUT (pid:4381)
2014-12-11 18:12:00 [21401] [INFO] Booting worker with pid: 21401
2014-12-11 18:12:00 [21402] [INFO] Booting worker with pid: 21402

There is a possible solution to the problem on the Internet, the essence of which is to increase nginx proxy_read_timeout and supervisor timeout for Gunicorn. But this, it seems to me, does not solve the problem at the root, I would like to dissect in more detail, analyze the situation. How would you colleagues act in this situation? What should you pay attention to first of all, what tools would you use?
Or increasing proxy_read_timeout & timeout - is this the right decision and I have focused on this in vain?