PHP-FPM high load causes 502 Bad Gateway Error resolution

The way to resolve 502 Bad Gateway is:

1. Depending on the performance of the server, in the php-fmp.conf to increase the value of Max_children, I currently use 15.

(a php-fpm uses about 20M of RAM, if your memory is about 1G,1024/20=50)

2. Use the reload parameter to reload the PHP-FPM periodically. Release the memory used by PHP-FPM, the PHP script execution time is too long to cause memory to use excessively, overload php-fpm can eliminate this problem. How to completely resolve the php-cgi script takes up a lot of memory and results in a 502 error. It is worth exploring further, and this is a good way to do so.

The practice is to use crontab to let php-fpm smooth restart, so that the PHP script does not affect the operation.

*/30 * * * */usr/local/php/etc/php-fpm.conf Reload