SAR: Receiver-Driven Transport Protocol With Micro-Burst Prediction in Data Center Networks

Abstract

In recent years, motivated by new datacenter applications and the well-known shortcomings of TCP in data center, many receiver-driven transport protocols have been proposed to provide ultra-low latency and zero packet loss by using the proactive congestion control. However, in the scenario of mixed short and long flows, the short flows with ON/OFF pattern generate micro-burst traffic, which significantly deteriorates the performance of existing receiver-driven transport protocols. Firstly, when the short flows turn into ON mode, the long flows cannot immediately concede bandwidth to the short ones, resulting in queue buildup and even packet loss. Secondly, when the short flows change from ON to OFF mode, the released bandwidth cannot be fully utilized by the long flows, leading to serious bandwidth waste. To address these issues, we propose a new receiver-driven transport protocol, called SAR, which predicts the micro burst generated by short flows and adjusts the sending rate of long flows accordingly. With the aid of micro-burst prediction mechanism, SAR mitigates the bandwidth competition due to the arrival of short flows, and alleviates the bandwidth waste when the short flows leave. The testbed and NS2 simulation experiments demonstrate that SAR reduces the average flow completion time (AFCT) by up to 66% compared to typical receiver-driven transport protocols.