Dynamic priority coflow scheduling in optical circuit switched networks

OCS (Optical Circuit Switch) is increasingly popular for accelerating data transmission of coflows due to its higher bandwidth and lower power consumption compared with EPS (Electronic Packet Switch), where a coflow is a collection of related parallel flows between two computation stages in data-intensive applications. However, the extra port constraints and reconfiguration delay of OCS obstruct the efficiency of OCS operations. This paper studies the problem of coflow scheduling in the OCS of datacenter networks to minimize the total Coflow Completion Time (CCT). We propose a Dynamic Priority Coflow Scheduling Algorithm that schedules coflows preemptively by considering coflow transmission time and OCS reconfiguration delay jointly to dynamically update each coflow's priority, which can significantly reduce the waiting time of small coflows and reduce head-of-line blocking. Extensive simulations based on Facebook data traces show that our approach outperforms the state-of-the-art scheme OMCO [19] significantly, and transmits multiple coflows 1.30× faster than OMCO.