Install PHP-FPM on Gentoo Linux

PHP-FPM (FastCGI Process Manager) is a high-performance PHP handler.

Step 1 – Install PHP-FPM

# Set PHP_TARGETS and USE flags in /etc/portage/make.conf:
# PHP_TARGETS="php8-2"
# USE="... fpm opcache mysql"
emerge --ask dev-lang/php

Step 2 – Start and enable the service

rc-update add php-fpm default && rc-service php-fpm start

Step 3 – Verify

php --version
php-fpm -v 2>/dev/null || php-fpm8.3 -v 2>/dev/null || php-fpm8.2 -v

Step 4 – Key configuration file

The main pool configuration is at /etc/php/fpm-php8.2/fpm.d/www.conf. Important settings:

; Run as web server user
user = www-data
group = www-data

; UNIX socket (preferred over TCP for local use)
listen = /run/php-fpm/www.sock
listen.owner = www-data
listen.group = www-data

; Process management
pm = dynamic
pm.max_children = 20
pm.start_servers = 5
pm.min_spare_servers = 2
pm.max_spare_servers = 10
pm.max_requests = 500

Apply changes:

systemctl reload php-fpm 2>/dev/null || rc-service php-fpm reload 2>/dev/null || rcctl reload php83_fpm