Issues and Evaluations of Caching Solutions for Web
Application Acceleration
Wen-Syan Li Wang-Pin Hsiung Dmitri V. Kalashnikov
Oliver Po Divyakant Agrawal K. Sel(;uk Candan
Radu Sion
C&C Research Laboratories- Silicon Valley
10080 North Wolfe Road, Suite SW3-350
Cupertino, California 95014, USA
Email: { wen,whsiung,dvk,sion, oliver, agrawal,candan } nec. corn
Response time is a key differentiation among
electronic commerce (e-commerce) applica-
tions. For many e-commerce applications,
Web pages are created dynamically based
on the current state of a business stored in
database systems. Recently, the topic of Web
acceleration for database-driven Web applica-
tions has drawn a lot of attention in both the
research community and commercial arena.
In this paper, we analyze the factors that have
impacts on the performance and scalability of
Web applications. We discuss system archi-
tecture issues and describe approaches to de-
ploying caching solutions for accelerating Web
applications. We give the performance matrix
measurement for network latency and various
system architectures. The paper is summa-
rized with a road map for creating high per-
formance Web applications.
1 Introduction
For most Web sites, their contents are fairly static and
can be generated in advance to serve a large number of
requests. However, due to the dynamic nature of elec-
tronic commerce (e-commerce), e-commerce Web sites
are usually database-driven and their contents change
more frequently to reflect the current business state
in the database systems. Architectural designs for a
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Proceedings of the 28th VLDB Conference,
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high performance e-commerce Web site is challenging
because it involves integration of content delivery net-
works, caching appliances, Web servers, application
servers, and databases.
Response time and reliability are two key points of
differentiation among e-commerce Web sites. In busi-
ness terms, the brand name of an e-commerce site is
correlated to the type of experience users receive. The
need to account for users' quality perception in de-
signing Web servers for e-commerce systems has been
highlighted in [1]. Snafus and slow-downs at major
Web sites during special events or peak times demon-
strate the difficulty of scaling up e-commerce sites.
Slow response times and down times can be devas-
tating for e-commerce sites as reported in a study
by Zona Research[2] on the relationship between Web
page download time and user abandonment rate. The
study shows that only 2% of users will leave a Web
site (i.e. abandonment rate) if the download time is
less than 7 seconds. However, the abandonment rate
jumps to 30% if the download time is around 8 sec-
onds. The abandonment rate reaches 70% as down-
load times exceed 12 seconds. This study clearly es-
tablishes the importance of fast response times to an
e-commerce Web site to retain its customers.
In technical terms, ensuring the timely delivery of
fresh dynamic content to end-users and engineering
highly scalable e-commerce Web sites for special peak
access times put heavy demand on IT staff. This
is compounded by the ever-changing complexity of
e-commerce applications. For many e-commerce ap-
plications, Web pages are created dynamically based
on the current state of a business, such as product
prices and inventory, stored in database systems. This
characteristic requires e-commerce Web sites to de-
ploy cache servers, Web servers, application servers,
and database systems at the backend.
Applying caching solutions for Web applications
and content distribution has received a lot of atten-
tions in the Web and database communities. In this
paper, we analyze the issues of caching dynamic con-

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