Optimal Polling for Latency-Throughput Tradeoffs in Queue-Based Network Interfaces for Clusters

We consider a networking subsystem for message–passing clusters that uses two unidirectional queues for data transfers between the network interface card (NIC) and the lower protocol layers, with polling as the primary mechanism for reading data off these queues. We suggest that for accurate mathematical analysis of such an organization, the values of the system’s states probabilities have to be taken into consideration, in addition to the well–known mean–value estimates. A single server single queue polling system with server’s “vacations” is then articulated via an M/G/1 queueing model. We present a method for obtaining the values of system’s states probabilities in such a scheme that can be used to identify “sweet spots” of the polling period that result in a reasonable compromise between the message passing latency and the overall system’s throughput.