Rails3: Is there a server-side analytics?

Is there a server-side analytics for Rails?

Thanks

Have you tried Newrelic: http://newrelic.com/

NewRelic - real-time monitoring of Rails, DB, Memcache, Background taks

Cacti / Nagious - monitoring CPU, LA, RAM, IO, NET over SNMP

updated I'd like to suggest you the video discussion by Mark Imbriaco (37signals admin)

There was one a year ago called Weed-3 but I do not believe there is any that work with Rails 3 currently.