Subject: paper on improving Webserver performance
To: None <tech-net@netbsd.org>
From: Mohit Aron <aron@cs.rice.edu>
List: tech-net
Date: 07/06/1999 16:36:36
Hi,
I'd like to tell the NetBSD community about a recent paper that I
wrote. The paper is entitled "TCP Implementation Enhancements for Improving
Webserver Performance" and can be downloaded from:
http://cs-tr.cs.rice.edu/Dienst/UI/2.0/Describe/ncstrl.rice_cs/TR99-335/
The abstract for the paper is attached below. Perhaps the people who maintain
the TCP code in the NetBSD project might be interested in incorporating the
proposals made in the paper.
- Mohit Aron
aron@cs.rice.edu
Abstract:
This paper studies the performance of BSD-based TCP implementations in
Web servers. We find that lack of scalability with respect to high TCP
connection rates reduces the throughput of Web servers by up to 25%
and imposes a memory overhead of up to 32 MB on the kernel.
We also find that insufficient accuracy in TCP's timers results in overly
conservative delays for retransmission timeouts, causing
poor response time, low network utilization and throughput loss. The paper
proposes enhancements to the TCP implementation that eliminate
these problems, without requiring changes to the protocol or the API.
We also find that conventional benchmark environments do not fully expose
certain significant performance aspects of TCP implementations and propose
techniques that allow these benchmarks to more accurately predict the
performance of real servers.