Non-Splitting Coflow Scheduling with Provable Guarantees in Heterogeneous Parallel Networks
Abstract
As a prominent network abstraction, coflow models efficiently capture communication patterns in data centers. Since coflow scheduling in large-scale data centers is NP-hard, the existing literature has predominantly focused on limited environments with m=2 network cores, relying on flow splitting, which introduces substantial operational overhead. Crucially, no approximation algorithm with provable performance guarantees has been proposed for the more practical, non-splitting coflow scheduling problem, even for the m=2 case, let alone for general hybrid architectures. To bridge this critical gap, this paper investigates the non-splitting problem within a hybrid, heterogeneous parallel network featuring multiple network cores (m 2) composed of Electronic Packet Switches (EPS), not-all-stop Optical Circuit Switches (OCS), and all-stop OCS. We propose three unified polynomial-time approximation algorithms that minimize the makespan and the total weighted coflow completion time across this hybrid environment without incurring any splitting overhead. Let τ denote the maximum flow degree across all ports in the network, and let m be the number of network cores. To minimize the makespan, our algorithm achieves an approximation ratio of 2\2τ-1, m+τ-1\ in the hybrid architecture. To minimize the total weighted coflow completion time, our algorithm achieves an approximation ratio of 16\2τ-1, 2m+τ-1\ in the hybrid architecture. Moreover, we characterize the approximation ratios of our algorithm under different architectural combinations.