Using Multiple Authentication Methods with Impala
Impala 2.0 and later automatically handles both Kerberos and LDAP authentication. Each impalad daemon can accept both Kerberos and LDAP requests through the same port. No special actions need to be taken if some users authenticate through Kerberos and some through LDAP.
Prior to Impala 2.0, you had to configure each impalad to listen on a specific port depending on the kind of authentication, then configure your network load balancer to forward each kind of request to a DataNode that was set up with the appropriate authentication type. Once the initial request was made using either Kerberos or LDAP authentication, Impala automatically handled the process of coordinating the work across multiple nodes and transmitting intermediate results back to the coordinator node.