public static String getMasterAddr(Configuration conf) throws UnknownHostException {
    String masterAddrFromConf = conf.get(MASTER_ADDRS_KEY);
    if (!Strings.isNullOrEmpty(masterAddrFromConf)) {
      return masterAddrFromConf;
    }
    String hostname = getHostname(conf, ServerType.MASTER);
    int port = conf.getInt(HConstants.MASTER_PORT, HConstants.DEFAULT_MASTER_PORT);
    return String.format("%s:%d", hostname, port);
  }
Builds the default master address end point if it is not specified in the configuration.
<p/>
Will be called in {@code HBaseTestingUtility}.
hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterRegistry.java