FDRC - Flow duration time based rate control in data center networks

Abstract

Data Center is now becoming an important facility for many applications (e.g, web search and retail). As TCP can't meet applications' demands for latency and throughput, many tcp-based protocols (e.g, DCTCP, D2TCP, L2DCT) have been proposed. Among them, protocols such as D2TCP incorporate explicit deadline into congestion window adjustment procedure to guarantee flows' latency and protocols such as L2DCT consider flow size when computing congestion window adjustment factor to guarantee the throughput of short flows. These two methods work well at some scenery but they have some deficiencies on two aspects. Firstly, we find that they can only reduce the percentage of flows missing deadline or reduce flow completion time, but can not meet both the goals simultaneously. Secondly, most of these methods need the user to know flow information (e.g, deadline, flow size), which may be hard to know exact value beforehand. In this paper, we advocate to use flow duration time into congestion window adjustment procedure. Based on this, we propose FDRC-Flow Duration Time based Rate Control algorithm. We find that without knowing flow information beforehand, FDRC can achieve the goal of reducing the percentage of flows missing deadline and cutting average flow completion time simultaneously. We theoretically analyze FDRC's behavior and implement FDRC into ns-2 as well as linux kernel. Our experiments show that FDRC performs better than D2TCP and L2DCT at nearly all the scenarios. On average, it performs 30% better than the state-of-art deadline-aware congestion control protocol D2TCP and 10% better than the state-of-art flowsize-aware protocol L2DCT.