A customer has a file /grid/RangerUserSync.txt , where written items are put and they are then synced into Ranger.
When the file is updated, users are not created in the Ranger UI as expected.
This was due to a configuration issue:
a) ranger.usersync.filesource.file was set to the default value. This was changed to /grid/RangerUserSync.txt and then Ranger was restarted via Ambari.
b) The configuration "ranger.usersync.source.impl.class" had to be set to "org.apache.ranger.unixusersync.process.FileSourceUserGroupBuilder". Then Ranger was restarted via Ambari and users were then automatically created/synced up.