FastReChain: A Novel Bidirectional Model-Based Algorithm for Topology Engineering of OCS-Based Clusters

TL;DR

FastReChain is a new bidirectional model-based algorithm designed to efficiently perform topology engineering in OCS-based data center clusters, reducing runtime and minimizing link modifications during reconfiguration.

Contribution

The paper introduces a novel bidirectional modeling approach and the FastReChain algorithm, improving efficiency and reducing link impact compared to existing ILP and greedy methods.

Findings

FastReChain outperforms ILP-based algorithms in runtime efficiency.

The algorithm reduces link modifications during topology reconfiguration.

Simulation results based on real-trace data validate its effectiveness.

Abstract

Optical Circuit Switching (OCS) technology is increasingly being adopted in data centers due to its advantages of low power consumption and low technology refresh costs. Unlike electrical packet switches, OCS provides programmable bandwidth for directly connected devices by configuring the mapping relationships of internal ports. Thus, how to calculate these internal port mapping relationships, i.e., Topology Engineering (ToE), is one of the key designs of OCS-based clusters. Current deployments usually design ToE algorithms by solving Integer Linear Programming (ILP) models, with the aim of minimizing modifications to links occupied by running tasks as much as possible. However, ILP-based ToE algorithms may incur excessive runtime overhead in large-scale clusters. Some existing ToE algorithms convert the ILP model into a Minimum-Cost Flow model through greedy construction, yet such greedy strategies may increase the number of affected links during the OCS reconfiguration process. To solve the aforementioned problems, we propose a novel bidirectional modeling approach, along with a corresponding FastReChain algorithm in this paper. We verify the superiority of this algorithm through simulation experiments based on real-trace data.