INFO [main-SendThread(localhost:12181):ClientCnxn$SendThread@959] - Socket connection established, initiating session, client: /xxxxxx:38806, server: localhost/xxxxx:12181 INFO [main-SendThread(localhost:12181):ClientCnxn$SendThread@1240] - Unable to read additional data from server sessionid 0x0, likely server has closed socket, closing socket connection and attempting reconnect
Zookeeper报错：Unable to read additional data from server sessionid 0x0, likely server has closed socket, closing socket connection and attempting reconnect
报错原因可能是由于整个集群超过半数机器宕机（或有些机器实际并未启动），zookeeper会认为集群处于不可用状态
此报错主要原因在于：
由于配置文件zoo.cfg配置错误，导致机器实际没有起来，zk服务不可用。
查看存活zk节点数量，检查zoo.cfg配置文件，避免因为配置文件错误导致zk节点宕机。
