I faced similar issue, but REST api thru -   http://localhost:8080/api/v1/cluster/[cluster_name]/services/KERBEROS  was not available, and kerberos remove was giving error - "The 'krb5-conf' configuration is not available" in ambari-server.log   We had Ambari 2.7.5.0. In that version clusterconfigmapping is not present, we had to do below procedure:   In ambari db -  psql -U ambari -d ambari (default password: bigdata) ambari=> select config_id, selected, create_timestamp from clusterconfig where type_name in ('kerberos-env', 'krb5-conf'); config_id | selected | create_timestamp -----------+----------+------------------ 352 | 0 | 1589796215822 452 | 0 | 1589800820822 << Select the record with latest timestamp 353 | 0 | 1589796215857 453 | 0 | 1589800820858 <<Select the record with latest timestamp (4 rows) ambari=> update clusterconfig set selected=1 where config_id=452; UPDATE 1 ambari=> update clusterconfig set selected=1 where config_id=453; UPDATE 1 ambari=> update clusterconfig set selected=1 where config_id=452; update clusterconfig set selected=1 where config_id=453;   * Still the kerberos REST api was not been shown. * Remove the kerberos * Add kerberos back ... View more