Nginx + php-fpm "504 Gateway Time-out"

If your Nginx + php-fpm returns 502 or 504 Error then you can try following:

If these 2 didn’t work (and you’re still running php-fpm through TCP then check how many connections are open: netstat | grep 9000. If there are many CLOSE_WAIT connections then the solution is to set a request_terminate_timeout=30s in your /etc/php5/fpm/pool.d/www.conf file (like here).

This will allow killing TCP connections that didn’t close for different reasons after max 30 sec.