看到这篇文章（http://ihower.tw/rails3/deployment.html）讲常用的有三种模式：
Unicorn http://unicorn.bogomips.org/ (Multi-processed模型)
Thin http://code.macournoyer.com/thin/ (Evented-driven模型)
Puma http://puma.io/ (Multi-threaded模型)
他们各有什么特点呢？Event Driven该怎么理解？
迷茫2017-04-22 08:58:15
Found a very comprehensive answer: http://stackoverflow.com/questions/4113299/ruby-on-rails-server-options
