private String[][] parseDataDirs(String dataDirs) {
    String[] tiers = dataDirs.split(IoTDBConstant.TIER_SEPARATOR);
    String[][] tierDataDirs = new String[tiers.length][];
    for (int i = 0; i < tiers.length; ++i) {
      tierDataDirs[i] = tiers[i].split(",");
      for (int j = 0; j < tierDataDirs[i].length; j++) {
        tierDataDirs[i][j] = tierDataDirs[i][j].trim();
      }
    }
    return tierDataDirs;
  }
load a property file and set TsfileDBConfig variables.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBDescriptor.java