CDH开启高可用后,NameNode主备节点切换
获取Namenode ID
查看nn1的状态
hdfs haadmin -getServiceState namenode30 #standby hdfs haadmin -getServiceState namenode37 #active
修改nn2为standby状态
hdfs haadmin -transitionToStandby --forcemanual namenode37
修改nn1为active状态
hdfs haadmin -transitionToActive --forcemanual namenode30