TCP Stalls at the Server Side: Measurement and Mitigation
TCP Stalls at the Server Side: Measurement and Mitigation
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DOI：
10.1109/tnet.2018.2886282
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Jianer Zhou;Zhenyu Li;Qinghua Wu;P. Steenkiste;S. Uhlig;Jun Yu Li;Gaogang Xie
中科院分区：
文献类型：
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作者：
Jianer Zhou;Zhenyu Li;Qinghua Wu;P. Steenkiste;S. Uhlig;Jun Yu Li;Gaogang Xie
TCP是影响Internet应用程序用户感知性能的重要因素。诊断TCP性能问题背后的原因对于更好地理解TCP当前的缺点至关重要。本文提出了一个TCP流性能分析框架，分类TCP失速的原因。该框架构成了我们用来分析流行服务提供商部署的三种服务（云存储、软件下载和Web搜索）的数据包级跟踪的工具的基础。我们发现，多达20%的流量停滞了一半的生命周期。网络相关的原因，特别是超时重传，占主导地位的摊位。对超时重传暂停原因的分析表明，双重重传和尾部重传是最主要的原因。然而，这些原因的重要性取决于具体的服务。基于这些观察，我们提出了智能重传超时（S-RTO），一种通过仔细和温和的侵略重传来减轻超时重传停顿的机制。S-RTO在受控网络和生产网络中进行评估。结果一致表明，它是有效地提高TCP性能，特别是短流。
TCP is an important factor affecting user-perceived performance of Internet applications. Diagnosing the causes behind TCP performance issues in the wild is essential for better understanding the current shortcomings in TCP. This paper presents a TCP flow performance analysis framework that classifies causes of TCP stalls. The framework forms the basis of a tool that we use to analyze packet-level traces of three services (cloud storage, software download, and web search) deployed by a popular service provider. We find that as many as 20% of the flows are stalled for half of their lifetime. Network-related causes, especially timeout retransmissions, dominate the stalls. A breakdown of the causes for timeout retransmission stalls reveals that double retransmission and tail retransmission are among the top contributors. The importance of these causes depends however on the specific service. Based on these observations, we propose smart-retransmission time out (S-RTO), a mechanism that mitigates timeout retransmission stalls through careful and gentle aggression for retransmission. S-RTO is evaluated in a controlled network and also in a production network. The results consistently show that it is effective at improving TCP performance, especially for short flows.