CODACS project: level-node communication policies

Nodes in the CODACS prototype are connected in a WK-recursive topology. Since such a system can scale up to thousand nodes, simple policies are required to efficiently manage internode communication, specially when groups of cooperating nodes need to exchange groups of related information. The solution proposed for this collective communication resides in treating message transfer as communication among homologous level-nodes. This solution, which takes advantage of recursive network properties, allows each gather node of a sender level-node (1) to identify the correct message sequence; (2) to evaluate the quantum to assign to the scheduler; (3) to transfer the sequence as a unique message. The resulting message is then transferred to homologous ones of a receiver level-node by a level-channel in pipeline fashion to speed up the throughput. Delivering activity occurs adopting a straightforward communication algorithm.