The ability of a server to be in a state to perform a required function at a given instant of time or at any instant of time within a given time interval. From the user point of view, availability over a specified time interval is the percentage of that interval during which the system was available for normal use.
Published in Chapter:
Performance Analysis and Models of Web Traffic
Federico Montesino Pouzols (University of Seville, Spain), Angel Barriga Barros (University of Seville, Spain), Diego R. Lopez (RedIRIS, Spain), and Santiago Sánchez-Solano (CSIC - Scientific Research Council, Spain)
Copyright: © 2008
|Pages: 8
DOI: 10.4018/978-1-59904-885-7.ch157
Abstract
The Internet and, more specifically, Web-based applications now provide the first-ever global, easy-to-use, ubiquitous and economical communications channel. Most companies have already automated their operations to some extent, which enhances their ability to interact with other companies electronically. With the advent of Web services, the interaction between companies becomes easier and more transparent (Khalaf, Curbera, Nagy, Tai, Mukhi, & Duftler, 2005). Web-based technologies are extensively employed and support core components of virtual and networked organizations. Many of them, including for instance Web-based communities, heavily rely on Web traffic. Additionally, Web technologies play a central role in the technologies for supporting industrial virtual enterprises (VE) being developed by the National Industrial Information Infrastructure Protocols Consortium (NIIIP). Thus, modelling and analysis techniques for Web traffic become important tools for performance analysis of virtual organizations (Malhotra, 2000; Foster, Kesselman, & Tuecke, 2001). This article overviews current models of Web traffic as well as performance analysis of Web-based systems.