When using BDR with Kerberos authentication enabled, BDR requires all the ports listed on the following page: Port Requirements for Backup and Disaster Recovery.

Additionally, the port used for the Kerberos KDC Server and KRB5 services must be open to all hosts on the destination cluster. By default, this is port 88.

  Note: These steps also enable Hive/Impala replication with Kerberos. The additional steps in Hive/Impala Replication are only required if the source and destination clusters use a Cloudera Manager version before 5.12.

1. On the hosts in the destination cluster, ensure that the krb5.conf file (typically located at /etc/kbr5.conf) on each host has the following information:
   • The kdc information for the source cluster's Kerberos realm. For example:

     [realms]
      SOURCE.MYCO.COM = {
       kdc = src-kdc-1.src.myco.com:88
       admin_server = src-kdc-1.src.myco.com:749
       default_domain = src.myco.com
      }
      DEST.MYCO.COM = {
       kdc = dest-kdc-1.dest.myco.com:88
       admin_server = dest-kdc-1.dest.myco.com:749
       default_domain = dest.myco.com
      }

   • Domain/host-to-realm mapping for the source cluster NameNode hosts. You configure these mappings in the [domain_realm] section. For example, to map two realms named SRC.MYCO.COM and DEST.MYCO.COM, to the domains of hosts named hostname.src.myco.com and hostname.dest.myco.com, make the following mappings in the krb5.conf file:

     [domain_realm]
      .src.myco.com = SRC.MYCO.COM
      src.myco.com = SRC.MYCO.COM
      .dest.myco.com = DEST.MYCO.COM
      dest.myco.com = DEST.MYCO.COM

2. On the destination cluster, use Cloudera Manager to add the realm of the source cluster to the Trusted Kerberos Realms configuration property:
   1. Go to the HDFS service.
   2. Click the Configuration tab.
   3. In the search field type "Trusted Kerberos" to find the Trusted Kerberos Realms property.
   4. Enter the source cluster realm.
   5. Enter a Reason for change, and then click Save Changes to commit the changes.
3. In the search field, type "domain name".
4. Enter the domain names for Kerberos.
5. If domain_realm is configured in the Advanced Configuration Snippet (Safety Valve) for remaining krb5.conf, remove the entries for it.
6. If your Cloudera Manager release is 5.0.1 or lower, restart the JobTracker to enable it to pick up the new Trusted Kerberos Realm settings. Failure to restart the JobTracker prior to the first replication attempt may cause the JobTracker to fail.

1. Perform the procedure described in the previous section, including restarting the JobTracker.
     Note: If the source and destination clusters both run Cloudera Manager 5.12 or higher, you can skip steps 2 and 3 in this section. These additional steps are no longer required for Hive/Impala replication. When you complete the configuration steps in HDFS Replication, you also configure Hive/Impala replication..
2. On the hosts in the source cluster, ensure that the krb5.conf file on each host has the following information:
   • The kdc information for the destination cluster's Kerberos realm.
   • Domain/host-to-realm mapping for the destination cluster NameNode hosts.
3. On the source cluster, use Cloudera Manager to add the realm of the destination cluster to the Trusted Kerberos Realms configuration property.
   1. Go to the HDFS service.
   2. Click the Configuration tab.
   3. In the search field type "Trusted Kerberos" to find the Trusted Kerberos Realms property.
   4. Enter the destination cluster realm.
   5. Enter a Reason for change, and then click Save Changes to commit the changes.

   It is not necessary to restart any services on the source cluster.

As part of Test Connectivity, Cloudera Manager tests for properly configured Kerberos authentication on the source and destination clusters that run the replication. Test Connectivity runs automatically when you add a peer for replication, or you can manually initiate Test Connectivity from the Actions menu.

This feature is available when the source and destination clusters run Cloudera Manager 5.12 or later. You can disable the Kerberos connectivity test by setting feature_flag_test_kerberos_connectivity to false with the Cloudera Manager API: api/<version>/cm/config.

If the test detects any issues with the Kerberos configuration, Cloudera Manager provides resolution steps based on whether Cloudera Manager manages the Kerberos configuration file.