Unable to start failover controller. Parent znode does not exist.
./bin/zkCli.sh -server master1
ls /
没有看到/hadoop-ha
解决方法：
进入hadoop namenode服务器
./bin/hdfs zkfc -formatZK
在两个namenode节点上启动zkfc服务
./sbin/hadoop-daemon.sh start zkfc
查看master1节点状态
./bin/hdfs haadmin -getServiceState master1
active
actice namenode节点转移
./bin/hdfs haadmin -failover master1 master2
查看是否转移
./bin/hdfs haadmin -getServiceState master1
standby
./bin/hdfs haadmin -getServiceState master2
active
参考：
https://blog.csdn.net/houzhizhen/article/details/44099825
ZKFC服务异常：Parent znode does not exist.
原文：http://blog.51cto.com/xiaoxiaozhou/2140896