PHP-FPM (FastCGI Process Manager) is an essential service that manages PHP requests on a web server. Restarting PHP-FPM is often required after making configuration changes, updating PHP versions, or troubleshooting issues. This guide will show different methods to restart PHP-FPM based on your server’s operating system and PHP version.

1. Restart PHP-FPM Using systemctl (Modern Linux Systems)

Most modern Linux distributions, including Ubuntu, Debian, CentOS, and RHEL, use systemd to manage services. Use the following command:

sudo systemctl restart php-fpm

For specific PHP versions (e.g., PHP 7.4 or PHP 8.1), specify the version:

sudo systemctl restart php7.4-fpm
sudo systemctl restart php8.1-fpm

To check the status of PHP-FPM:

sudo systemctl status php-fpm

2. Restart PHP-FPM Using service (Older Systems)

Some older Linux distributions use the service command instead of systemctl:

sudo service php-fpm restart

For specific PHP versions:

sudo service php7.4-fpm restart
sudo service php8.1-fpm restart

3. Restart PHP-FPM Using init.d (Legacy Systems)

On legacy systems that still rely on SysVinit, restart PHP-FPM with:

sudo /etc/init.d/php-fpm restart

For a specific PHP version:

sudo /etc/init.d/php7.4-fpm restart

4. Reload PHP-FPM Without Dropping Connections

Instead of a full restart, you can reload PHP-FPM to apply changes without terminating existing connections:

sudo systemctl reload php-fpm

For specific PHP versions:

sudo systemctl reload php7.4-fpm

5. Stop and Start PHP-FPM Manually

If a restart command doesn’t work, manually stopping and starting PHP-FPM can help:

sudo systemctl stop php-fpm
sudo systemctl start php-fpm

6. Kill and Restart PHP-FPM Processes

If PHP-FPM is unresponsive, manually kill all processes and restart:

sudo pkill -9 php-fpm
sudo systemctl start php-fpm

Conclusion

Restarting PHP-FPM is a crucial step in maintaining web server performance and applying configuration changes. Depending on your Linux distribution and PHP version, you can use systemctl, service, init.d, or manual process termination to restart PHP-FPM effectively.