报错：
2021-02-13 05:10:59,304 INFO [main] retry.RetryInvocationHandler (RetryInvocationHandler.java:log(411)) - org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.ipc.StandbyException): Operation category READ is not supported in state standby. Visit https://s.apache.org/sbnn-error
at org.apache.hadoop.hdfs.server.namenode.ha.StandbyState.checkOperation(StandbyState.java:98)
at org.apache.hadoop.hdfs.server.namenode.NameNode$NameNodeHAContext.checkOperation(NameNode.java:2017)
解决方案
rm -rf /opt/module/hadoop-3.1.3/logs
rm -rf /opt/module/hadoop-3.1.3/data
rm -rf /tmp/hadoop/dfs重新格式化hadoop的namenode
出现原因：虚拟机直接关机
