After debugging for 6-hours - I am giving this up :| We have a nginx+php-fpm+mysql in LAN with almost 100 wordpress (created and used by different designers/developers all working on test wordpres setup) We are using nginx without any issues from long. Today, all of a sudden - nginx started returning "504 Gateway Time-out" out of the blue... I checked nginx error log for a virtual host... 2010/09/
![Nginx + php-fpm "504 Gateway Time-out" error with almost zero load (on a test-server)](https://cdn-ak-scissors.b.st-hatena.com/image/square/1d7824625a3ecbc3a39062b14aaa9db8a44aa022/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fserverfault%2FImg%2Fapple-touch-icon%402.png%3Fv%3D9b1f48ae296b)