Error when root executes Hadoop command:

[root@vmocdp125 conf]# hadoop fs -ls /user/
[INFO] 17:50:42 main [RetryInvocationHandler]Exception while invoking getFileInfo of class ClientNamenodeProtocolTranslatorPB over vmocdp127.test.com/172.16.145.127:8020. Trying to fail over immediately.144
org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.ipc.StandbyException): Operation category READ is not supported in state standby
	at org.apache.hadoop.hdfs.server.namenode.ha.StandbyState.checkOperation(StandbyState.java:87)
	at org.apache.hadoop.hdfs.server.namenode.NameNode$NameNodeHAContext.checkOperation(NameNode.java:1932)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkOperation(FSNamesystem.java:1313)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getFileInfo(FSNamesystem.java:3861)
	at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.getFileInfo(NameNodeRpcServer.java:1076)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.getFileInfo(ClientNamenodeProtocolServerSideTranslatorPB.java:843)
	at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
	at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2151)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2147)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:422)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
	at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2145)

	at org.apache.hadoop.ipc.Client.call(Client.java:1427)
	at org.apache.hadoop.ipc.Client.call(Client.java:1358)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
	at com.sun.proxy.$Proxy9.getFileInfo(Unknown Source)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:771)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:252)
	at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:104)
	at com.sun.proxy.$Proxy10.getFileInfo(Unknown Source)
	at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:2116)
	at org.apache.hadoop.hdfs.DistributedFileSystem$22.doCall(DistributedFileSystem.java:1315)
	at org.apache.hadoop.hdfs.DistributedFileSystem$22.doCall(DistributedFileSystem.java:1311)
	at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
	at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1311)
	at org.apache.hadoop.fs.Globber.getFileStatus(Globber.java:57)
	at org.apache.hadoop.fs.Globber.glob(Globber.java:252)
	at org.apache.hadoop.fs.FileSystem.globStatus(FileSystem.java:1655)
	at org.apache.hadoop.fs.shell.PathData.expandAsGlob(PathData.java:326)
	at org.apache.hadoop.fs.shell.Command.expandArgument(Command.java:235)
	at org.apache.hadoop.fs.shell.Command.expandArguments(Command.java:218)
	at org.apache.hadoop.fs.shell.Command.processRawArguments(Command.java:201)
	at org.apache.hadoop.fs.shell.Command.run(Command.java:165)
	at org.apache.hadoop.fs.FsShell.run(FsShell.java:287)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:76)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:90)
	at org.apache.hadoop.fs.FsShell.main(FsShell.java:340)
Found 6 items
drwxrwx---   - ambari-qa hdfs          0 2016-09-14 19:48 /user/ambari-qa
drwxr-xr-x   - hcat      hdfs          0 2016-09-14 20:09 /user/hcat
drwx------   - hdfs      hdfs          0 2016-09-20 18:51 /user/hdfs
drwxr-xr-x   - hive      hdfs          0 2016-09-14 20:11 /user/hive
drwxr-xr-x   - hdfs      hdfs          0 2016-09-20 18:49 /user/ocetl
drwxrwxr-x   - spark     hdfs          0 2016-09-14 20:00 /user/spark

Change to hdfs to execute the command can be: sudo -u hdfs hadoop fs -ls /user

[root@vmocdp125 conf]# sudo -u hdfs hadoop fs -ls /user
Found 6 items
drwxrwx---   - ambari-qa hdfs          0 2016-09-14 19:48 /user/ambari-qa
drwxr-xr-x   - hcat      hdfs          0 2016-09-14 20:09 /user/hcat
drwx------   - hdfs      hdfs          0 2016-09-20 18:51 /user/hdfs
drwxr-xr-x   - hive      hdfs          0 2016-09-14 20:11 /user/hive
drwxr-xr-x   - hdfs      hdfs          0 2016-09-20 18:49 /user/ocetl
drwxrwxr-x   - spark     hdfs          0 2016-09-14 20:00 /user/spark