PHP-FPM Domain Pools

Last modified: January 18, 2021


This document explains how the system creates a domain pool with PHP-FPM.

How does the system create pools?

The system creates a pool when the /var/cpanel/userdata/[user]/[domain].php_fpm.yaml configuration file exists in the domain. This file must include the following lines:

_is_present: 1

You may place any desired pool values in this file.

  • You must include the --- line above the pool values in this file.
  • The _is_present value is optional, but you must include it if you do not set any other values in the file.
Exercise extreme caution when you manually edit .yaml files. Incorrect syntax in these files will cause services to fail. We strongly recommend that you create a backup of your system before you manually edit .yaml files.
This file only contains the differences of directives from the built-in default directives.

Create a pool

To create a pool, run the Cpanel::PHPFPM::rebuild_files() function.

You may also run the /scripts/php_fpm_config --rebuild script to create a pool.

The system will perform the following steps:

  • The system scans for the /var/cpanel/ApachePHPFPM/system.yaml and /var/cpanel/ApachePHPFPM/system_pool_defaults.yaml files and then generates a system configuration for each of the PHP versions.

  • The system searches for the domain’s yaml files.

  • The system generates a line in the /opt/cpanel/[ea_php_version]/root/etc/php-fpm.d/[domain].conf file for every domain.yaml file.

  • To direct the requests to the php_fpm daemon with Apache, the system modifies the httpd.conf file with the rebuild_files() script to resemble the following example:

# php -- BEGIN cPanel-generated handler, do not edit
<FilesMatch ".(phtml|php[0-9]*)$">
    SetHandler "proxy:unix:/home/cptest3/cptest3_tld.php_fpm.sock|fcgi://cptest3.tld/"
# php -- END cPanel-generated handler, do not edit

The system removes any existing conf files that do not contain a corresponding domain.yaml file.

The system creates the FPM socket in the /opt/cpanel/phpversion/root/usr/var/run/php-fpm/obscure_domain.sock directory, where phpversion represents the version of PHP, and obscure_domain represents a hashed version of the domain. Your hashed version will resemble the following example:


When the pool and system configurations exist in their designated locations, the system restarts the pools. The method that the system uses to restart them depends on whether it runs as a systemd or an init.d system. The system then removes any PHP version pools that do not hold domains with that version.

Jail shell

When you create a PHP-FPM domain pool, if the following conditions exist, the system automatically binds them to the virtfs mount:

  • The /var/cpanel/feature_toggles/apachefpmjail file exists.
  • The WHM account uses either the jailshell or noshell settings.
  • You enabled the Experimental: Jail Apache Virtual Hosts using mod_ruid2 and cPanel┬« jailshell setting in the Security section of WHM’s Tweak Settings interface (WHM » Home » Server Configuration » Tweak Settings).

Additional Documentation