@John Cleveland
Good to know that your issue is resolved. Few details: hadoop.proxyuser.<USER>.hosts From File View perspective: Here we need to replace the <USER> with the username who is actually running the Ambari Server (Or Standalone Ambari FileView Server) . So if you are running ambari server as "root" user then you will need to set the property for "root" user as "hadoop.proxyuser.root.groups". The Value of this property can be a comma separated list of addresses where you are running the ambari server (OR Standalone View Ambari Server for hosting the View) . Because View Server will actually send requests to Hadoop. So hadoop need to allow access from the host where the FileView is running. Setting * means you can use the FileView (Standalone Ambari View Server) which is installed to any host. (In a kerberized environment we need to replace the <USER> with the ambari server kerberos principal name). From Generic Hadoop Perspective: In general, By Using proxy user using properties "hadoop.proxyuser.$superuser.hosts" along with either or both of "hadoop.proxyuser.$superuser.groups" and "hadoop.proxyuser.$superuser.users".
By specifying as below in core-site.xml, the superuser named super can connect only from host1 and host2 to impersonate a user belonging to group1 and group2.
Following document explains it with examples: https://hadoop.apache.org/docs/r2.7.3/hadoop-project-dist/hadoop-common/Superusers.html
... View more
