multiple nginx passenger processes!?

hi, when i look into my running processes, i can see multiple processes like this one

Passenger RubyApp: /rorapps/fooo/production/foooo_com/current/public (product

each with 400-500mb memory consumption

is this normal?

Yes.

That is not unusual, the size depends on what the app is doing, a
simple app may have processes of around 200MB. You can get further
information using
sudo passenger-memory-stats

Colin