Approximate Multicast Coflow Scheduling in Reconfigurable Data Center Networks

The emerging optical circuit technology, capable of establishing circuit connections among switches, has been proposed as a promising paradigm for data center networks. This paper investigates the problem of minimizing the completion time of multicast coflow in optical circuit switches (OCS)-based data center networks. The existing works either only focused on multicast coflow scheduling or focused solely on circuit scheduling in OCS-based networks, which greatly limits their performance. Hence, in this paper, we study how to reduce the completion time of multicast flows by considering circuit scheduling and coflow scheduling simultaneously. Firstly, We formulate the problem of multicast coflow scheduling, and prove it to be NP-hard. We propose a delay-efficient multicast coflow scheduling algorithm by integrating coflow scheduling with circuit scheduling. The proposed algorithm is proved to have an approximate ratio of at most \(2\sqrt{n}\) , where n represents the number of optical circuit switches. Through extensive simulations, it is shown that the proposed algorithm can achieve high performance compared to state-of-the-art methods.