getting "ERROR: unable to read what child say: Bad file descriptor (9)" in php7.2-fpm.log

Question

I am getting the "ERROR: unable to read what child say: Bad file descriptor (9)" randomly on the production server and these error come conseuctivly more than 10 time after which php crashes Image from the php7.2-fpm.log file. But some times after this error php gets reloaded automatically

What can be the possible reasons for this behaviour and what can be the possible fix of this issue

Answer 1

This error is specific to PHP-FPM (FastCGI Process Manager), looks like you have a communication problem between the PHP-FPM master process and its child processes.

Check if the system has reached the maximum file description limit

Ulimit -n

additionally check your PHP-FPM configuration files ((php 7.2)usually located in /etc/php/7.2/fpm/). also check the settings for operating systems, such as pm.max_children, pm.start_servers, and pm.min_spare_servers.

:)