1. A method of pacing network traffic among a plurality of compute nodes connected using a data communications network, the network having a plurality of network regions, the plurality of compute nodes distributed among these network regions, the method comprising: identifying, by a compute node for each region of the network, a roundtrip time delay for communicating with at least one of the compute nodes in that region; sharing, by the compute node with all other compute nodes in the same network region as the compute node, the roundtrip time delay identified for each region of the network; determining, by the compute node for each region, a pacing algorithm for that region in dependence upon the roundtrip time delay for that region; and transmitting, by the compute node, network packets to at least one of the compute nodes in at least one of the network regions in dependence upon the pacing algorithm for that region.