PHP-FPM (FastCGI Process Manager) is the recommended way to run PHP behind Nginx. It manages PHP worker processes efficiently, supports dynamic/static/ondemand process management, and provides per-pool configuration for multi-tenant servers. This guide configures PHP-FPM 8.4 with Nginx on Ubuntu 26.04 LTS.

Tested and valid on:

Ubuntu 26.04 LTS

Prerequisites

Ubuntu 26.04 LTS with Nginx installed
PHP 8.4-FPM installed
A user with sudo privileges

Step 1 – Install PHP-FPM

sudo apt install php8.4-fpm -y
sudo systemctl status php8.4-fpm

Step 2 – Configure the PHP-FPM Pool

The default pool is www.conf:

sudo nano /etc/php/8.4/fpm/pool.d/www.conf

Key settings to review:

[www]
user = www-data
group = www-data
listen = /run/php/php8.4-fpm.sock
pm = dynamic
pm.max_children = 25
pm.start_servers = 5
pm.min_spare_servers = 5
pm.max_spare_servers = 10

Step 3 – Configure Nginx to Use PHP-FPM

In your Nginx server block, add:

location ~ .php$ {
    try_files $uri =404;
    fastcgi_split_path_info ^(.+.php)(/.+)$;
    fastcgi_pass unix:/run/php/php8.4-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include fastcgi_params;
}

Step 4 – Test Configuration

sudo php-fpm8.4 -t
sudo nginx -t

Step 5 – Restart Both Services

sudo systemctl restart php8.4-fpm
sudo systemctl reload nginx

Step 6 – Create a Per-App Pool (optional)

For multi-site isolation, create a dedicated pool:

sudo cp /etc/php/8.4/fpm/pool.d/www.conf /etc/php/8.4/fpm/pool.d/myapp.conf
sudo nano /etc/php/8.4/fpm/pool.d/myapp.conf

Change the pool name, socket, and user:

[myapp]
user = myappuser
listen = /run/php/php8.4-myapp.sock

Step 7 – Monitor FPM Status

Enable the FPM status page in the pool config:

pm.status_path = /fpm-status

Add a restricted location in Nginx:

location /fpm-status { allow 127.0.0.1; deny all; fastcgi_pass unix:/run/php/php8.4-fpm.sock; include fastcgi_params; }

curl http://localhost/fpm-status

Conclusion

PHP-FPM 8.4 is now properly configured with Nginx on Ubuntu 26.04 LTS. Tune the process manager settings based on available RAM and expected concurrency for optimal performance.

How to Configure PHP-FPM with Nginx on Ubuntu 26.04