Hani Jamjoom and Kang G. Shin
IEEE/ACM Transactions on Networking
volumne, No. 2, April 2006
Abstract. Flash crowd events (FCEs) present a real threat to the
stability of routers and end-servers. Such events
are characterized by a large and sustained spike in
client arrival rates, usually to the point of
service failure. Traditional rate-based drop
policies, such as Random Early Drop (RED), become
ineffective in such situations since clients tend to
be persistent, in the sense that they make multiple
retransmission attempts before aborting their
connection. As it is built into TCP’s congestion
control, this persistence is very widespread, making
it a major stumbling block to providing responsive
aggregate traffic controls. This paper focuses on
analyzing and modeling the effects of client
persistence on the controllability of aggregate
traffic. Based on this model, we propose a new drop
strategy called persistent dropping to regulate the
arrival of SYN packets and achieves three important
goals: 1) it allows routers and end-servers to
quickly converge to their control targets without
sacrificing fairness; 2) it minimizes the portion of
client delay that is attributed to the applied
controls; and 3) it is both easily implementable and
computationally tractable. Using a real
implementation of this controller in the Linux
kernel, we demonstrate its efficacy, up to 60% delay
reduction for drop probabilities less than 0.5.
Keywords. Active queue management, aggregate traffic control, flash crowds, persistent dropping.
Bibtex.
@article{jamjoom-ToN-06,
author = {Hani and Jamjoom and Kang G. and Shin},
title = {{On the Role and Controllability of Persistent Clients in Traffic Aggregates}},
journal = {IEEE/ACM Transactions on Networking},
volume = {14},
number = {2},
month = {April},
year = {2006}
}