@Predrag Minovic If the LDAP server is and Active Directory, you should make sure that the sync settings are similar to what is presented in this example: https://docs.hortonworks.com/HDPDocuments/Ambari-2.2.1.0/bk_Ambari_Security_Guide/content/_example_active_directory_configuration.html I think the reason that you are not getting all of the users you expect is because in an Active Directory, the CN is typically auto-generated using the user's first and last name where the sAMAccountName is explicitly set as the userid (or username). However, it is possible to manually set the CN to the username and thus this is probably why you are getting some and not all of the expected results. ... View more