Create php-fpm processes on demand, not dynamic

php-fpm/templates/pool.conf.j2

@@ -7,8 +7,7 @@ listen = /run/php/{{ fpm_pool }}-fpm.sock
 listen.owner = {{ fpm_socket_user }}
 listen.group = {{ fpm_socket_group }}
 
-pm = dynamic
-pm.max_children = 5
-pm.start_servers = 2
-pm.min_spare_servers = 1
-pm.max_spare_servers = 3
+pm = ondemand
+pm.max_children = 10
+pm.process_idle_timeout = 10s
+pm.max_requests = 500