Additionally it is definitely not stateless, the session cache persists between requests as well. You can just load balance between 20 php-fpm instances without moving the session cache to something shared.
You can do persistent connections but it only applies to the same child process and you don't have fine grain control over this process if you choose to use it.
Session cache is stored on disk.
Additionally it is definitely not stateless, the session cache persists between requests as well. You can just load balance between 20 php-fpm instances without moving the session cache to something shared.