@Override
  public void close() throws IOException {
    if (channel != null) {
      if (channel.isOpen()) {
        channel.force(true);
      }
      fileOutputStream.close();
      fileOutputStream = null;
      channel.close();
      channel = null;
    }
  }
LogWriter writes the binary logs into a file using FileChannel together with check sums of each
log calculated using CRC32.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/writelog/LogWriter.java