code: private static String buildMetricPathPrefix(String configuredMetricPathPrefix) {
          if (configuredMetricPathPrefix != null) {
              return configuredMetricPathPrefix;
          }
          String hostname;
          try {
              hostname = InetAddress.getLocalHost().getHostName().replaceAll("\\.", "_");
          } catch (UnknownHostException e) {
              hostname = "#unknown#";
          }
          return String.format(DEFAULT_METRIC_PATH_PREFIX_FORMAT, hostname);
      }
docs: {@link java.net.InetAddress#getLocalHost()} may not be known at JVM startup when the process is launched as a Linux service.