code: public void start() {
      Preconditions.checkState(mBackup == null);
      long delayedTimeInMillis = getTimeToNextBackup();
      mBackup = mScheduledExecutor.scheduleAtFixedRate(this::dailyBackup,
          delayedTimeInMillis, FormatUtils.parseTimeSize("1day"), TimeUnit.MILLISECONDS);
      LOG.info("Daily metadata backup scheduled to start in {}",
          CommonUtils.convertMsToClockTime(delayedTimeInMillis));
    }
docs: Starts {@link DailyMetadataBackup}.