WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

Question

I'm getting this error:

WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

When trying to access my XenForo installation at forums.domain.com in my PHP error log.

It happens every time, and I think it's causes PHP to crash, which prevents the other site on the same box from working as well.

I'm using nginx with two server blocks for these two sites. One's under new. and one's under forums..

Thanks.

Solution 1

Configure your Pool pm.* directives & reload/restart PHP - http://www.php.net/manual/en/install.fpm.configuration.php

pm.max_children int

The number of child processes to be created when pm is set to static and the maximum number of child processes to be created when pm is set to dynamic. This option is mandatory.

This option sets the limit on the number of simultaneous requests that will be served. Equivalent to the ApacheMaxClients directive with mpm_prefork and to the PHP_FCGI_CHILDREN environment variable in the original PHP FastCGI.

Solution 2

On Ubuntu 12 (and probably elsewhere), the pm.max_children value is set in the configuration file /etc/php5/fpm/pool.d/www.conf. Search the file for that string and increase the value. Restart PHP for the change to take effect with this command:

 sudo service php5-fpm restart

If you are using Apache, you may need to restart that service first.

Comments

[David Yell]

This answer needs more explanation, such as which setting and where to find it, how to change it.

[Jadeye]

Same for 7.4: grep -s 'max_children' /etc/php/7.4/fpm/pool.d/{*,.*} /etc/php/7.4/fpm/pool.d/www.conf:; static - a fixed number (pm.max_children) of child processes;