public static String generateClusterName(Configuration conf) {
    String hosts = HiveConf.getTrimmedVar(conf, ConfVars.LLAP_DAEMON_SERVICE_HOSTS);
    return hostsRe.matcher(hosts.startsWith("@") ? hosts.substring(1) : hosts).replaceAll("_");
  }
Login using kerberos and also updates the current logged in user

@param principal  - kerberos principal
@param keytabFile - keytab file
@throws IOException - if keytab file cannot be found
llap-common/src/java/org/apache/hadoop/hive/llap/LlapUtil.java