This article mainly introduced Opcache caused php-fpm collapse Nginx return 502 of the solution, very practical, the need for friends can refer to the
I this blog in order to improve operational efficiency in the VPS mounted Opcache expansion, the results found that there is a page return 502, the other page normal.
Check the PHP-FPM log, found that the PHP-FPM process does not know why the crash, and then the Opcache off on the normal. The process of the middle toss does not mention, in short the final discovery should be and another extension Zend guard conflict caused, funny, as long as I php.ini [Zend Guard] Configuration segment in [Zend Opcache] after the normal.
Do not want to continue to delve, if you are familiar with the bottom of PHP, you can give me some doubts.