public void forceCloseAllProcessor() throws TsFileProcessorException {
    LOGGER.info("Start force closing all database processor");
    List<Future<Void>> tasks = new ArrayList<>();
    for (DataRegion dataRegion : dataRegionMap.values()) {
      if (dataRegion != null) {
        tasks.add(
            cachedThreadPool.submit(
                () -> {
                  dataRegion.forceCloseAllWorkingTsFileProcessors();
                  return null;
                }));
      }
    }
    checkResults(tasks, "Failed to force close processor.");
  }
flush command Sync asyncCloseOneProcessor all file node processors.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/StorageEngine.java