http://www.cnblogs.com/01-sunkey/archive/2012/04/09/2438538.html
http://www.cnblogs.com/ruiqingzhang/p/5534099.html
http://www.cnblogs.com/shanyou/p/3221990.html
zookeeper
原文：http://www.cnblogs.com/valor-xh/p/6185298.html
