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Nathan C. Burnett, Ph.D.
Alumnus
Computer Sciences
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Exploiting Gray-Box Knowledge of Buffer-Cache Management
Nathan C. Burnett,
John Bent,
Andrea C. Arpaci-Dusseau, and
Remzi H. Arpaci-Dusseau
Department of Computer Sciences,
University of Wisconsin-Madison
{ncb, johnbent, dusseau, remzi}@cs.wisc.edu
Abstract:
The buffer-cache replacement policy of the OS can have a
significant impact on the performance of I/O-intensive applications.
In this paper, we introduce a simple fingerprinting tool, Dust,
which uncovers the replacement policy of the OS. Specifically, we are
able to identify how initial access order, recency of access,
frequency of access, and long-term history are used to determine which
blocks are replaced from the buffer cache. We show that our
fingerprinting tool can identify popular replacement policies
described in the literature (e.g., FIFO, LRU, LFU, Clock, Random, Segmented
FIFO, 2Q, and LRU-K) as well as those found in current systems
(e.g., NetBSD, Linux, and Solaris).
We demonstrate the usefulness of fingerprinting the cache replacement
policy by modifying a web server to use this knowledge; specifically,
the web server infers the contents of the OS file cache by modeling
the replacement policy under the given set of page requests. We show
that by first servicing those web pages that are believed to be
resident in the OS buffer cache, we can improve both average response
time and throughput.
Full Paper: Postscript PDF
Publications
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