此文绝对给力http://www.infoq.com/cn/news/2007/09/ruby-1-9-fibers
http://www.igvita.com/2009/05/13/fibers-cooperative-scheduling-in-ruby/
http://www.mikeperham.com/2010/03/30/using-activerecord-with-eventmachine/
http://www.mikeperham.com/2010/04/03/introducing-phat-an-asynchronous-rails-app/
http://www.igvita.com/2010/04/15/non-blocking-activerecord-rails/