digraph  {
    rankdir=LR
    compound=true
    node [shape="plaintext"];
    transfer->transferRead; transfer->transferWrite;
    transferRead->transferReadSendData[lhead=cluster_transferRead]
    subgraph cluster_transferRead{
        {
        rank=same;
        transferGetFile->transferSendType->transferReadSendData->transferRecvID;
        }
    }

}

我希望群集在右侧，从上到下。但是从上到下。如何解决？