Paper on Performance of Web Proxy Caching in Heterogeneous Bandwidth Environments

From: Anja Feldmann (anja@research.att.com)
Date: Fri, Apr 09 1999


Date: Fri, 9 Apr 1999 14:40:09 -0400 (EDT)
Message-Id: <199904091840.OAA23935@spectrum.research.att.com>
From: Anja Feldmann <anja@research.att.com>
To: www-wca@w3.org
Subject: Paper on Performance of Web Proxy Caching in Heterogeneous Bandwidth Environments


The following paper just appeared at IEEE INFOCOM 1999

Title:    Performance of Web Proxy Caching 
                                   in Heterogeneous Bandwidth Environments

Authors:  Anja Feldmann, Ramon Caceres, Fred Douglis, Gideon Glass,
 	                                              Michael Rabinovich. 

Pointers: "http://www.research.att.com/~anja/feldmann/papers/infocom99_proxim.ps"
          "http://www.research.att.com/~anja/feldmann/papers/infocom99_proxim.ps.gz"

Abstract:

   Much work on the performance of Web proxy caching has focused on high-level
   metrics such as hit rates, but has ignored low-level details such as 
   cookies, aborted connections, and persistent connections between clients
   and proxies as well as between proxies and servers.  These details have a
   strong impact on performance, particularly in heterogeneous bandwidth
   environments where network speeds between clients and proxies are
   significantly different than speeds between proxies and servers.

   We evaluate through detailed simulations the latency and bandwidth effects
   of Web proxy caching in such environments.  We drive our simulations with
   packet traces from two scenarios: clients connected through slow dialup
   modems to a commercial ISP, and clients on a fast LAN in an industrial
   research lab.  We present three main results.  One, caching persistent
   connections at the proxy can improve latency much more than simply caching
   Web data.  Two, aborted connections can waste more bandwidth than that
   saved by caching data.  Three, ``cookies'' can dramatically reduce hit
   rates by making many documents effectively uncacheable.