PowerFCT: Power Optimization of Data Center Network with Flow Completion Time Constraints

Power optimization is a challenging task for a large scale data centre. Among all the major power consumption contributors of the entire data centre, data centre networks (DCNs) can account for up to 20% of the total power consumption. To save power for DCNs, several different approaches have been proposed. Unfortunately, none of these approaches addresses the performance impact on the flow completion times (FCTs) of delay-sensitive flows. In fact, FCTs of the delay-sensitive flows have been identified as one of the most important service-level agreement metrics of the data centre networking services. In this paper, we propose Power FCT, a multi-dimensional DCN power saving scheme that jointly conducts traffic consolidation and leverages the different power states of multiple components inside the DCN switches, including CPU, network processor, switch fabric, packet buffer and cooling fans, to maximize the power savings for DCNs. In sharp contrast to existing work that neglects the performance impacts, PowerFCT features a novel FCT model and explicitly enforces the desired FCT requirements in the process of power optimization. As a result, the desired FCTs for delay-sensitive flows can be effectively maintained. Both hardware experiments and simulation evaluations show that PowerFCT can achieve the power savings up to 62% for DCNs, which outperforms two state-of-the-art schemes by 21% and 14%, respectively. For large-scale data centers, this savings can lead to millions of dollars of savings in operating expenses. In addition, PowerFCT has the lowest FCT miss ratio among all the solutions.