public static String getClientHostName() throws UnknownHostException {
    InetAddress address = LocalHostUtil.getLocalHost();
    return SocketCreator.use_client_host_name ? address.getCanonicalHostName()
        : address.getHostAddress();
  }
returns the hostname or address for this client
geode-core/src/main/java/org/apache/geode/internal/net/SocketCreator.java