1. A method for performance by a coherency controller of a plurality of coherency controllers of a node having a plurality of sub-nodes, comprising: receiving by the coherency controller a transaction from one sub-node of the plurality of sub-nodes, the transaction relating to another sub-node of the plurality of sub-nodes; and, processing the transaction by the coherency controller without having to send the transaction to another coherency controller of the plurality of coherency controllers to which the transaction is related.