从SelectionKey拿出attach的NIOServerCnxn，处理IO
QuorumPeerMain
ServerSocketChannel
保存NIOServerCnxn
QuorumPeer
WorkerSender
cluster mode
ServerConfig
监听OP_ACCEPT事件
runFromConfig
IOWorkRequest
AcceptThread
ServerCnxnFactory
客户端网络通信组件
standalone mode
启动后台线程
startServerCnxnFactory
start
WorkerReceiver
AdminServer
WorkerService
解析配置文件
SelectionKey
Watch status of ZooKeeper server. It will do a graceful shutdownif the server is not running or hits an internal error.
ServerCnxnFactory管理与客户端的通信默认NIOServerCnxnFactory
启动AdminServer
ZooKeeperServerMain
SocketChannel
ConnectionExpirerThread
QuorumPeerConfig
FastLeaderElection
构造
join
SelectorThread
分桶清理过期连接
shutdownLatch.await()
监听OP_READ
NIOServerCnxn管理与某一个客户端的连接
attach
loadDataBase
FileTxnSnapLog
