http://www.ibm.com/developerworks/cn/opensource/os-cn-zookeeper/ （Zookeeper入门配置）
http://www.54chen.com/java-ee/zookeeper-curator.html （zookeeper-curator使用）
http://kb.cnblogs.com/page/86827/ （ZooKeeper解惑)
http://stblog.baidu-tech.com/?p=1164 (Zookeeper工作原理,包括leader)
zk client源码剖析
0. new ZkClient("10.232.68.58", 30000, 20000, new ZipZkSerializer());
1. ZkConnection.connect()
2. org.I0Itec.zkclient.ZkConnection.connect(Watcher watcher) 内部包装org.apache.zookeeper.ZooKeeper
3. org.I0Itec.zkclient.ZkClient.retryUntilConnected()
Quota限制
quotaDataNode 用来设定限制条件，比如每条子树的最大长度，大小等，用来防止失控的程序不停添加新内容导致整个系统崩溃
JIRA任务 https://issues.apache.org/jira/browse/ZOOKEEPER-231
使用方法见 ZooKeeper Quota’s Guide
比如在zookeeper shell中输入如下命令 list quota /zoo
返回结果absolute path is /zookeeper/quota/zoo/zookeeper_limits
quota for /zoo does not exist.
其中的/zookeeper/quota/zoo/zookeeper_limits指明了quota存储的地方。但是目前没有quota。
楼江航的总结：
zookeeper学习记录
http://agapple.iteye.com/blog/1111377
zookeeper学习记录(二)
http://agapple.iteye.com/blog/1112032
zookeeper学习记录三(session,watcher,persit机制)
http://agapple.iteye.com/blog/1292129
zookeeper OOM问题排查
http://agapple.iteye.com/blog/1741921
zookeeper项目使用几点小结
zookeeper watcher使用注意点
http://agapple.iteye.com/blog/1685957
zookeeper学习&使用系列文章
http://agapple.iteye.com/blog/1292473
需要精读的官方文章：
http://zookeeper.apache.org/doc/trunk/zookeeperObservers.html
http://zookeeper.apache.org/doc/r3.2.2/zookeeperQuotas.html
关于Barriers参考,深入浅出 Barriers 实现（一）
http://www.cnblogs.com/haippy/archive/2012/12/26/2833554.html
http://jm-blog.aliapp.com/?p=1384
zookeeper使用和原理探究（一）
http://www.blogjava.net/BucketLi/archive/2010/12/21/341268.html