Site settings allow to select between different PHP modes:
- PHP as an Apache module
Using any module different form “Apahe module” allow you to change a PHP version if it is installed.
Let's take a closer look at each mode.
PHP as Apache module
This mode uses a system-default PHP version. In this case Nginx becomes a Frontend server and Apache as a Backend. Apache operates in MPM ITK mode which allows sites to operate under a separate user.
This mode allows switching between PHP versions. Apache operates as a Backend server and creates a separate PHP processing process for each request.
This mode allows switching between PHP versions. Apache operates as a Backend server but in FCGI case processes are being kept in the server memory and process several requests which speeds up PHP scripts processing which, in turn, affects a site working speed. It is recommended to use this mode when an alternative PHP version is used.
This mode allows switching between PHP versions. In this case PHP-FPM is used as a Backend server and Nginx stays as a Frontend server. It is required to keep in mind that in this mode .htaccess files can not be processed and all .htaccess settings has to be converted into Nginx configuration.