Re-synchronization and Controllability of Bursty Service Requests

, and
IEEE/ACM Transactions on Networking
Vol. 12, No. 4,
Abstract. There is an increasing prevalence of interactive Web sessions in the Internet. These are mostly short-lived TCP connections that are delaysensitive and have transfer times dominated by TCP backoffs, if any, during connection establishment. Unfortunately, arrivals of such connections at a server tend to be bursty, and can trigger multiple retransmissions, resulting in long average client-perceived delays. Traditional traffic control mechanisms, such as token bucket filters, are designed to complement admission control mechanisms, by regulating throughput, bounding service times, and protecting systems from overload. However, they cannot control connection-establishment delays, and thus, do not provide effective control of client-perceived delays. We first present the surprising discovery of a re-synchronization property of retransmitted requests that exacerbates client-perceived delays when traditional control mechanisms are used. Then, we introduce a novel, multi-stage filtering scheme called Abacus Filters (AFs) that limits the client-perceived delay while maximizing server throughput even in the case of bursty connection arrivals. Analysis of delay-control properties of various filtering mechanisms is presented, along with a detailed performance evaluation. AFs are shown to exhibit tight delay control and better complement traditional admission control policies.
Keywords. TCP Performance, TCP Measurements, SYN Packets, Admission Control, Re-synchronization
author = {Hani and Jamjoom and Padmanabhan and Pillai and Kang G. and Shin},
title = {{Re-synchronization and Controllability of Bursty Service Requests}},
journal = {IEEE/ACM Transactions on Networking},
volume = {12},
number = {4},
month = {August},
year = {2004}