Enable manage.include.files for HDFS

Using Ambari Web, enable automated host participation by adding manage.include.files properties to the HDFS configuration.

When manage.include.files is configured and enabled, Ambari manages files that include and exclude hosts participating in cluster operations. Ambari also updates these files based on the state of hosts as displayed in Ambari Web. Add the manage.include.files=true and dfs.hosts properties to the HDFS configuration to enable automated host file participation for the HDFS service.

Using Ambari Web, browse to Services > HDFS.
In the Advanced hdfs-site configuration section, add the manage.include.files=true property.
In the Custom hdfs-site configuration section, ensure that the dfs.hosts property appears and that it is set to a valid location of the HDFS NameNode on the filesystem .
Also, ensure that the file exists and is owned by the user account being used to run the NameNode.

dfs.hosts=/etc/hadoop/conf/dfs.include
Restart services, as prompted by Ambari.

When manage.include.files is configured and enabled, Ambari manages files that include and exclude hosts participating in cluster operations.