@Override
  public void setMaxBytesCanReserve(long maxBytesCanReserve) {
    this.maxBytesCanReserve = maxBytesCanReserve;
    downStreamChannelList.forEach(
        sinkHandle -> sinkHandle.setMaxBytesCanReserve(maxBytesCanReserve));
  }
max bytes this ShuffleSinkHandle can reserve.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/exchange/sink/ShuffleSinkHandle.java