@Override
  public void close() throws IOException {
    if (logChannel != null) {
      try {
        if (logChannel.isOpen()) {
          logChannel.force(true);
        }
      } finally {
        logChannel.close();
        logStream.close();
      }
    }
  }
Minimum size to compress, use magic number 32 KB
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/dataregion/wal/io/LogWriter.java