private void checkClusterStillWritable() {
    try (Connection connection = EnvFactory.getEnv().getConnection();
        Statement statement = connection.createStatement()) {
      // check old data
      ResultSet resultSet = statement.executeQuery(COUNT_TIMESERIES);
      resultSet.next();
      Assert.assertEquals(1, resultSet.getLong(1));
      Assert.assertEquals(1, resultSet.getLong(2));
      LOGGER.info("Old data is still remain");
      // write new data
      statement.execute(INSERTION2);
      resultSet = statement.executeQuery(COUNT_TIMESERIES);
      resultSet.next();
      Assert.assertEquals(2, resultSet.getLong(1));
      Assert.assertEquals(2, resultSet.getLong(2));
      LOGGER.info("Region group is still writable");
    } catch (SQLException e) {
      LOGGER.error("Something wrong", e);
      Assert.fail("Something wrong");
    }
  }
Check whether the original DataNode's region file has been deleted.
integration-test/src/test/java/org/apache/iotdb/confignode/it/regionmigration/IoTDBRegionOperationReliabilityITFramework.java