code: private void dailyBackup() {
      try {
        BackupResponse resp = mMetaMaster.backup(BackupPOptions.newBuilder()
            .setTargetDirectory(mBackupDir).setLocalFileSystem(mIsLocal).build());
        if (mIsLocal) {
          LOG.info("Successfully backed up journal to {} on master {}",
              resp.getBackupUri(), resp.getHostname());
        } else {
          LOG.info("Successfully backed up journal to {}", resp.getBackupUri());
        }
      } catch (Throwable t) {
        LOG.error("Failed to execute daily backup at {}", mBackupDir, t);
        return;
      }
  
      try {
        deleteStaleBackups();
      } catch (Throwable t) {
        LOG.error("Failed to delete outdated backup files at {}", mBackupDir, t);
      }
    }
docs: The daily backup task.