[zookeeper] Zookeeper概述

1. Zookeeper客户端

Zookeeper
|
|--- ClientCnxn
|           |
|           |----SendThread
|           |
|           |----EventThread
|
|--- ZkWatchManager

　　在客户端中，SendThread和EventThread均使用BlockingQueue方式进行异步处理。

2. Zookeeper服务端

ZookeeperServer
|
|--- QuorumCnxManager
|           |
|           |---- RecvWorker
|           |
|           |---- SendWorker
|
|--- ZkWatcherManager
|
|--- RequestProcessors
|
|--- ZkDataBase(All in Memory)
|
|---- Load Data from Snapshot
|
|---- Sync Data from Leader
|
|---- Dump Data into disk

　　服务器中移除处理是通过阻塞队列完成。

3. 客户端与服务端交互