private void readStatsFromLocalBackupFile() {
    if (!Strings.isNullOrEmpty(config.localBackupFilePath)) {
      // load backup file and this backup is the previous stats
      ObjectMapper objectMapper = new ObjectMapper();
      try {
        this.previousHostAccountStorageStatsWrapper =
            objectMapper.readValue(new File(config.localBackupFilePath), HostAccountStorageStatsWrapper.class);
      } catch (Exception e) {
        this.previousHostAccountStorageStatsWrapper = null;
      }
    }
  }
Read all the container storage usage from local backup file.
ambry-mysql/src/main/java/com/github/ambry/accountstats/AccountStatsMySqlStore.java