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hadoopkerberoshadoop2

Secure Hadoop - Datanode cannot connect with namenode

I am using hadoop-2.6.0 and created HA enabled cluster with kerberos security in windows platform. Everything works fine if permission is set to false. But when I enable below property,

hdfs-site.xml

<property>
    <name>dfs.permissions</name>
    <value>true</value>
</property>

Datanode cannot connect with the namenode. I am getting the following exception

Exception

2015-05-21 10:44:42,461 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to server: kumar/192.168.3.4:9000
2015-05-21 10:44:46,079 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to server: dinesh/192.168.3.3:9000
2015-05-21 10:44:47,471 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to server: kumar/192.168.3.4:9000
2015-05-21 10:44:51,085 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to server: dinesh/192.168.3.3:9000
2015-05-21 10:44:52,477 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: Problem connecting to server: kumar/192.168.3.4:9000

I cannot find the exact root cause for this problem. I need help to solve this.

Solution

  • I just changed the default supergroup name to newly created group which has members of all hadoop users. Now all user in that group act as superuser hence it works fine.

    <property>
    <name>dfs.permissions.superusergroup</name>
    <value>Hadoopgroup</value>
</property>

    Refer superuser