Scaling for E-Business: Technologies, Models, Performance, and Capacity Planning

About

Features

• Focus on scalability and performance issues—Not found in other texts.

  • Shows students how security impacts technology. Ex.___

• Various numerical examples.

  • Helps students understand the performance impacts of security mechanisms. Ex.___

• Fundamental analytic techniques.

  • Enables students to understand the behavior of e-business systems and their customers. Ex.___

• Numerous diagrams throughout.

  • Provides students with easy-to-follow information regarding business relations and cycles to help them understand text concepts. Ex.___

• Chapter introductions and summaries.

  • Gives students an overview and recap of key points in each chapter. Ex.___

Description

In 1999, slow E-commerce sites cost their owners $44 billion in lost revenue -- and site failures have embarrassed companies from Britannica to eBay, Victoria's Secret to Charles Schwab. In Scaling for e-Business, two of the world's leading Web performance experts present powerful techniques for characterizing, predicting, anticipating, and addressing every aspect of E-commerce site performance. Scaling for e-Business demonstrates how to characterize E-commerce workloads more accurately than any book published yet. It clearly demonstrates techniques for analyzing the performance of authentication and payment services; modeling contention for software servers; modeling and planning for communications infrastructure; and most importantly, forecasting and addressing peak demand. Finally, the Web/E-Commerce developer will discover how to evaluate and project the long-term impact of changes in his/her site visitor profile -- even the growth of non-PC devices and traffic from "intelligent agents" such as comparative shopping bots.

Sample Content

Table of Contents

 1. Introduction.


 2. Customer Behavior Models.


 3. The Anatomy of E-business Transactions.


 4. Infrastructure for Electronic Business.


 5. A Quantitative Analysis of Authentication Services.


 6. A Quantitative Analysis of Payment Services.


 7. A Capacity Planning Methodology for E-business.


 8. Basic Performance Model Concepts.


 9. Characterizing E-commerce Performance Models.


10. Building E-commerce Performance Models.


11. Modeling Contention for Software Servers.


12. Modeling the Communication Infrastructure.


13. Forecasting the E-commerce Demand and Load.


14. A Complete E-commerce Case Study.


15. Concluding Remarks.


Appendix A: Glossary.

Preface

Preface

Goal, Theme, and Approach

The Internet is profoundly affecting almost all businesses and commerce paradigms. Global competition, industry traditions, laws, and consumer preferences are among the many issues being impacted by e-business. Weekly magazines and newspapers have dedicated large amounts of space to discuss e-business and the new economy. Newspapers publish news about e-business almost every day. However, there is good news and bad news. The good news is many innovative people are constantly creating new and exciting ways to use the Internet to provide novel, efficient, and convenient shopping paradigms as well as streamlining ways for businesses to do business with their partners. The bad news is the most successful e-business sites are at greater risks of being overwhelmed by large numbers of customers who can potentially bring the site operation to a halt. Scalability is then a challenge to the success of e-business. Our primary goal in writing this book was to create a framework in which e-business scalability could be discussed and evaluated.

This book presents a quantitative approach to understanding and analyzing e-business scalability based on a four-level reference model. The four-level model is composed of a business model, a functional model, a customer behavior model, and an IT resource model. This framework is used throughout the book to explain how e-business technologies work and how they impact performance, to characterize and forecast the workload of e-business sites, and to plan their capacity with the use of performance models.

New performance metrics for e-business are presented in the book. Models at the various levels of the reference model are used to represent and understand problems in e-business. These models include customer behavior models (e.g., Customer Behavior Model Graphs and Customer Visit Models), Client/Server Interaction Diagrams, and analytic (e.g., state transition diagrams and queuing networks) and simulation performance models. The combined use of these models provides a framework for assessing and evaluating the scalability of e-business sites.

Many examples derived from real e-business situations are used to illustrate the concepts presented in the book.

Who Should Read This Book

This book can be used by graduate and senior-level computer science students as well as students in e-commerce programs offered by business schools. Students of MBA programs with a concentration in information technology will also benefit from the concepts presented in this book. Many professionals can use this book as a reference or as a way to learn about e-commerce technologies and the quantitative methods used to evaluate and size e-commerce sites. Examples of such professionals include Webmasters of e-commerce sites and ISPs, CIOs, system architects, project managers of e-commerce companies, e-commerce application developers, capacity planners and performance analysts, designers of Internet-based products for e-commerce, and e-commerce consultants.

Book Organization

Part I: Modeling for E-Business

Chapter 1 presents a framework for analyzing and designing e-business sites. The framework is based on a four-level model that includes a business model, a functional model, a customer behavior model, and an IT resource model. The chapter discusses various types of electronic markets including various types of business-to-business, business-to-consumer, and consumer-to-consumer markets.

Chapter 2 discusses the motivations for capturing user behavior and presents customer models at various levels. The models presented in this chapter can be used to answer what-if questions at the customer behavior level and can serve as a basis to build models at the resource level. Two types of customer models are presented in this chapter: the Customer Behavior Model Graphs and the Customer Visit Model.

Chapter 3 discusses the anatomy of e-business functions from the logical view point. The chapter describes how software servers interact to implement e-business functions and provides a graphical notation—the Client/Server Interaction Diagrams—to describe these interactions. Several numerical examples illustrate how these diagrams can be used to answer quantitative questions about the execution of e-business functions.

Part II: Evaluating E-Business Infrastructure and Services

Chapter 4 describes the various elements that comprise the IT infrastructure needed to support e-businesses. The discussion includes hardware, software, and networking issues. Multi-tier website architectures, composed of dynamic load balancers, Web servers, application servers, and database servers, are described.

Chapter 5 presents a quantitative analysis of authentication services used in e-business. The chapter shows how the mechanisms and protocols used to support security may impact system performance. Many quantitative examples illustrate the tradeoffs between performance and security. In particular, the chapter analyzes how authentication protocols such as the Transport Layer Security (TLS) protocol, a successor of the Secure Sockets Layer (SSL) protocol, affects performance.

Chapter 6 provides an overview of what happens when one uses a credit card for payment in the physical world. Then, it discusses how Secure Electronic Transaction (SET) allows for credit card payments to take place over the Internet. The chapter describes SET at a high enough level of detail to provide the reader with an overall picture of the protocol as well as its performance implications. The performance of SET transactions is then discussed through various numerical examples. The chapter concludes with a brief discussion of other payment services.

Part III: Capacity Planning for E-Business

Chapter 7 contains an example-driven description of a capacity planning methodology for e-businesses. The methodology is composed of three planning activities: business and functional planning, customer behavior planning, and IT resource planning. Each of these activities is described in detail and illustrated with examples.

Chapter 8 provides insight and intuition regarding how simple performance models can be constructed, solved, and used in the context of electronic business environments. The fundamentals of performance models are then introduced. These include concepts such as service time, service demand, waiting time, response time, throughput, and performance laws. Scalability analysis techniques based on the study of performance bounds is presented here.

Chapter 9 starts by introducing very simple models. Complexity is progressively introduced and the solution to each model is presented using first principles and intuitive concepts. Two broad categories of models are covered in this chapter: system- and component-level models. System-level models treat the actual system as a black box that receives requests, processes them, and returns the results. Component-level models, based on queuing networks, in which components are represented by queues, allows one to explicitly represent processors, storage subsystems, networks, and routers.

Chapter 10 uses several examples to illustrate the performance impacts of contention for software resources (e.g., threads of a software server, database locks, and semaphores). Performance models that deal with software contention may be based on approximate analytic models or on simulation models. This chapter gives an overview of the techniques used to solve approximations that represent the effects of software contention. To show the impact of software contention, we discuss various results obtained by a combination of simulation and analytic models.

Chapter 11 presents a methodology for characterizing e-business workloads. In particular, the chapter shows how Customer Behavior Model Graphs (CBMGs) and Customer Visit Models (CVMs) can be obtained from HTTP logs and describes methods, based on clustering analysis, to derive small groups of CBMGs or CVMs that accurately represent the workload. The chapter also shows how the parameters for the resource models (e.g., queuing network models) can be derived from customer behavior models. Chapter 12 discusses techniques that can be used to analyze and forecast the demand for e-business sites. The chapter discusses traffic burstiness, traffic patterns in e-business, and forecasting techniques including regression methods, moving averages, and exponential smoothing. Logs of a real e-tailer are used to illustrate the traffic characteristics of an e-business site.

Part IV: Models for Specific E-Business Segments

Chapter 13 illustrates the use of the quantitative methods presented in the book through several examples in the business-to-consumer segment. A hypothetical electronic retailer is described. Then, different planning situations are discussed. In light of the models introduced throughout the book, we show how to tackle the problems and we present their solutions. The goal of the chapter is to guide the reader, in a step-by-step manner, through the model-based solution of a number of e-commerce examples.

Chapter 14 illustrates the use of the quantitative methods presented in the book through several examples in the business-to-business segment. An example of supply-chain integration and made-to-order computers is used to illustrate how capacity planning can be carried out in business-to-business environments. The chapter also shows how business-to-consumer transactions generate business-to-business transactions.

Part V: Summary, Challenges, and Perspectives

Chapter 15 concludes the book with a summary of important points covered in the book, challenges for e-business, and future perspectives. Appendix A contains a glossary of the important terms introduced in the book.

From the Same Authors

Menascé and Almeida co-authored the following books:

• Capacity Planning for Web Performance: Metrics, Models, and Methods, D. A. Menascé and V. A. F. Almeida, Prentice Hall, 1998.
• Capacity Planning and Performance Modeling: From Mainframes to Client-Server Systems, D. A. Menascé, V. A. F. Almeida, and L. W. Dowdy, Prentice Hall, 1994.

Book's Website and Authors' Addresses

Readers of this book can download the various MS Excel workbooks refer-enced in the various chapters from www.cs.gmu.edu/~menasce/ebook/. This website will also be used to keep the readers informed about new develop- ments related to the book. The authors' e-mail and postal addresses and websites are:

Prof. Daniel A. Menascé
Department of Computer Science, MS 4A5
George Mason University
Fairfax, VA 22030-4444
+1 703 993-1537
menasce@cs.gmu.edu
http://www.cs.gmu.edu/faculty/menasce.html

Prof. Virgilio A. F. Almeida
Department of Computer Science
Universidade Federal de Minas Gerais
P.O. Box 920
31270-010 Belo Horizonte, MG
Brazil
+55 31 499-5887
virgilio@dcc.ufmg.br
http://www.dcc.ufmg.br/~virgilio

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