How to use Nginx and PHP-FPM to load balance PHP requests across multiple servers?

To use Nginx and PHP-FPM to load balance PHP requests across multiple servers, you can follow these steps:

  1. Set up multiple PHP-FPM servers: Install PHP-FPM on each server that will handle PHP requests. You can configure PHP-FPM to listen on different ports on each server.

  2. Install and configure Nginx: Install Nginx on a separate server that will act as the load balancer. Configure Nginx to proxy PHP requests to the PHP-FPM servers.

    Here is a sample Nginx configuration file that serves as a load balancer:

    http {
        upstream php_servers {
            server php_server1:9000;
            server php_server2:9000;
            # Add more servers as per your requirement
        }
    
        server {
            listen 80;
            server_name example.com;
    
            location / {
                proxy_pass http://php_servers;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $host;
            }
        }
    }
    

    In the above configuration, php_server1 and php_server2 are the PHP-FPM servers listening on port 9000. Add more servers as per your requirement.

  3. Test the configuration and start the Nginx service: Verify the Nginx configuration for any syntax errors using nginx -t. If everything is fine, start the Nginx service.

  4. Adjust PHP-FPM configuration: Configure each PHP-FPM server to use a common network file system or shared database server to ensure session consistency across the servers. Update the php.ini file on each PHP-FPM server to configure session storage accordingly.

  5. Scale the setup: To add more PHP-FPM servers, simply install PHP-FPM on additional servers and update the Nginx configuration file by adding the new server's IP address and port to the php_servers upstream block.

By following these steps, you can effectively load balance PHP requests across multiple servers using Nginx and PHP-FPM.