Application Servers for E-Business

by Lisa E. Lindgren

Overview

The modern application server is a complex platform that is the linchpin of an enterprise environment that includes a very wide range of technologies-web document formatting, web protocols, server-side scripts, servlets, applets, programming languages, distributed object technologies, security capabilities, directory and naming services, load balancing, system management, and others. As such, it can be a daunting task to try to comprehend these systems. Application Servers for E-Business helps you understand the use of application servers in e-business. The book presents a comprehensive overview of the technologies related to application servers in their facilitation of E-business. These technologies include CORBA, Java, Enterprise Java Beans, Java 2, web servers, and legacy systems. It explores the role these servers play in the modern enterprise IT infrastructure and the environment in which they operate. The material also includes implementation considerations for application servers, including security, scalability, load balancing, and fault tolerance.

Chapter one provides an overview of application servers, the evolution of computing that took us from hierarchical, mainframe-centric environments to the web model of computing, and the rationale for E-commerce and E-business. Chapters two through five cover specific technologies, from web browsers and servers to applets and servlets. Chapter three provides an overview of Java technologies, and chapter four covers CORBA. Chapter five discusses application servers in detail. Since application servers are increasingly supporting the key mission-critical processes of an enterprise, it is critical that organizations deploying them build in "enterprise-class" facilities for security, scalability, load balancing, fault tolerance, and management. Chapter six discusses these deployment design issues. The book concludes with chapter seven, a chapter that presents several examples of the advantages of application ser

Product Details

ISBN-13:	9781138468566
Publisher:	CRC Press
Publication date:	09/30/2020
Pages:	282
Product dimensions:	7.00(w) x 10.00(h) x (d)

Read an Excerpt

Chapter 1: Introduction

To say that the World Wide Web has changed the face of computing is a vast understatement. In the first year or so of its existence, the Web was simply an interesting enhancement to the user interface of the Internet. Prior to the Web, the Internet was a network used heavily by government and educational institutions. The user interface of the Internet was character-based and cryptic, and therefore most users of the Internet were relatively sophisticated computer and network users. The Web offered a simple user interface and an easy way of interconnecting documents of related information. The Web technologies eventually evolved to support sophisticated interaction with users, which laid the groundwork for a new paradigm for transacting business. The Web has spawned entire new industries and has rendered the term "dot-com" a common adjective to describe the new companies and industries. The letter "e" (E) is being used to preface nouns, adjectives, and verbs and signifies the new electronic economy. The Web has created thousands of millionaires and billionaires from Internet initial public offerings (IPOs) and has leveled the playing field between new startups and established "brick-and-mortar" companies.

Economists regularly use the terms "new economy" to describe stocks and companies that enable an Internet model of doing business, and "old economy" to describe stocks and companies that sell goods and services in the traditional manner. The new-economy companies offer products or services for conducting business-to-consumer (B2C) and business-to-business (B2B) transactions. Yahoo!, America Online, eBay, and Amazon.com are premier examples ofnew-economy companies. While the new-economy companies have received a lot of press and have been the darlings of the NASDAQ stock market, the old-economy companies are not standing still. Almost without exception, they all have some form of Web presence and many are making dramatic movements in embracing the Web model of doing business. Economists and stock analysts are now saying that the old-economy companies, with their vast resources, brand recognition, and distribution channels, are poised to overtake many of their new-economy competitors. In fact, some analysts predict that some new-economy companies will cease to exist once their more traditional competitors ramp up the Web parts of their businesses.

Computing architectures have been changing rapidly to accommodate the new Web model of doing business. An application server is a relatively new breed of product that allows enterprises to augment their Web servers with new applications that are comprised of new business logic. Many application servers also integrate transactions and data from mission-critical, legacy hierarchical and client/server systems. Application servers represent the marriage of architectures. They allow organizations to build, deploy, and manage new applications that are based on the Web model but that integrate a wide variety of existing systems. Exhibit 1.1 depicts the very general architecture of an application server.

Before the Web, computing architectures evolved over years or even decades. The mainframe dominated computing from the 1960s until the 1980s. The mainframe model dictated a hierarchical architecture in which the mainframe controlled all communication, and end-user devices (terminals) had no local computing power.

With the advent of the personal computer and the intelligent workstation in the 1980s, the client/server era of computing began. Early advocates of client/server computing giddily pronounced the end of the mainframe era and the hierarchical model. In reality, there were several issues (cost, complexity, platform compatibility, and proprietary interfaces) that prevented the client/server architecture from completely replacing existing hierarchical systems. By the early 1990s, object-oriented architectures were being developed and deployed to overcome some of the problems with traditional client/server programming.

Then came the Web. With its ubiquitous user interface (the Web browser) and low cost of entry, the Web model quickly dominated. Enterprises of all sizes began to deploy Web servers for public access over the Internet, employee access over corporate intranets, and business partner access over corporate extranets. Throughout this book, the term "i*net" will be used to refer collectively to the Internet, intranets, and extranets. I*nets are, by definition, based on Web and Internet technologies. This means that they utilize TCP/IP as the networking architecture, Web browsers as the means of accessing information and applications, Web servers as the entry point (or "portal") to the enterprise, and Internet standard technologies for security, name resolution, and application deployment.

The application server is a special breed of product that spans the decades, seamlessly integrating the variety of different systems and architectures that a typical enterprise has deployed, and providing enterprise access to all i*net users. The application server is based on object technologies and has interfaces to visual development tools, allowing brand new applications to be built much more quickly than in the past. The object orientation promotes the ability to reuse code and potentially to integrate off-the-shelf, commercially available components, enhancing time-to-market and code quality. Application servers represent the pinnacle of server-based computing that integrates the high availability and advanced security capabilities demanded by today's enterprises. Application servers, in summary, facilitate the implementation of enterprisewide E-commerce and E-business systems.

The Evolution of Computing Architectures

Most enterprises have built their IT systems, applications, and infrastructure over a period of many years. The mission-critical systems have been created and fine-tuned to run the key business processes of the enterprise with 99.999% availability. In many cases, the mission-critical applications run on legacy systems and there is no compelling justification to move the applications to Web servers. The vast investment in building and maintaining these systems, estimated at trillions of dollars, must be protected because the scalability and reliability of the mission-critical systems have been proven over time.

However, enterprises that wish to harness the power of the Web to their advantage must find ways to integrate the new with the old. Because of the massive installed base of legacy equipment, systems, and applications, a brief overview of the evolution of computing architectures as implemented in enterprises is provided here. This is not an idle diversion into ancient history. The Web architects of today may need to accommodate a variety of legacy systems, architectures, and technologies if they hope to achieve full integration of the Web with their key business processes.

Legacy Systems

The early business computer systems were mainframe computers. Early mainframes were extremely expensive and somewhat rare. Programs and data were encoded on punched cards or tape and read into the system...

Table of Contents

1 Introduction — The Evolution of Computing Architectures — Legacy Systems — Client /Server — Distributed Object Model — Web Model — Electronic Commerce and Electronic Business — Three Stages of Web Presence — Electronic Commerce — Electronic Business — What Is an Application Server? — System Design Considerations — Security — Scalability — Load Balancing — Fault Tolerance — Management — Final Thoughts — 2 A Survey of Web Technologies — Overview of Web Browser and Server Operation — Document Formatting — HTML — XML — WML — Client-side Programs — Plug-ins — Java Applets — ActiveX Controls — Server-side Programs — Scripts, Forms, and APIs — Java Servlets and Java Server Pages — Active Server Pages — Server-side Programs versus Application Servers — Web-to-Host Solutions — Traditional Host Access — Applet-based Approaches — HTML Conversion Approaches — Host Integration Servers — Final Thoughts — 3 Java — History and Overview of Java — The Java Languages — Java — JavaScript — The Execution Environment — Java Virtual Machine — Java Runtime Environment — Java Development Kit — Java Components and APIs — JavaBeans — Enterprise JavaBeans — Enterprise Java APIs — Java 2 Platform — Java 2 Platform, Standard Edition — Java 2 Platform, Enterprise Edition — Java 2, Micro Edition — Final Thoughts — 4 CORBA — History and Overview of CORBA — CORBA Architecture — Interface Definition Language (IDL) — Object Request Broker (ORB) — Client Implementation and Interfaces — Server Object Implementation and Interfaces — CORBA Interoperability — Interoperability Architecture — Inter-ORB Bridges — General Inter-ORB Protocol (GIOP) — Internet Inter-ORB Protocol (HOP) — CORBA Interworking — Language Mappings — Final Thoughts — 5 Application Servers — Market Overview — Market Size and Growth — Market Drivers and Customer Requirements — Application Outsourcing — Diversity of Vendors and Solutions — Battle of the Component Models — Differentiation — Pricing Models — The Future of the Market — A General Architecture — Client Tier — Client Access — Client Architecture — Middle Tier — Elements in the Middle Tier — Web Server Application Server Design — Application Server Architecture — Application Server Platforms — Back-end Tier — Character-Based Systems — Databases — Transaction Processing Systems — Message Queuing Systems — Other Back-end Systems — Development Tools — Packaging — Related Products — Network-based Services — Directory Services — Queuing and Prioritization — Web Filtering and Caching — Load Balancers — Final Thoughts — 6 Design Issues for Enterprise Deployment of Application Servers — Security — Elements of Security — Java Security — CORBA Security — An Overall Security Architecture — Scalability — Scalability Defined — Network Scalability — Server Scalability — Application Server Scalability — Overall Scalability in Multi-tier Environments — Load Balancing — Geographic and Local Load Balancing — Load-balancing Approaches — Application Server Load Balancing — Fault Tolerance — Network Fault Tolerance — Server Fault Tolerance — Application Server Fault Tolerance — Management — Application Server Administration — End-to-End Management — Final Thoughts — 7 Trying It All Together — Implementation Examples — Case Study: Build Point Corporation — Case Study: FoliQuest International N.V — A Survey of Application Servers — Allaire Corporation — Art Technology Group (ATG) — BEA Systems — Bluestone Software — Gemstone Systems — HAHT Commerce, Inc — IBM — iE — Inprise Corporation — IONA Technologies — iPlanet — Microsoft — Oracle Corporation — Orbware Ltd — Persistence Software — SilverStream Software — Sybase, Inc — Summary of Offerings — A Look Ahead — About the Author — References — For More Information — Index.

Editorial Reviews

Targeting information technology managers and staff responsible for e- business solutions, independent consultant Lindgren explains application servers, the role they play in the modern enterprise IT structure, and the environment in which they operate. Technical descriptions and explanations of technologies such as CORBA, Java, Enterprise JavaBeans, Java 2, Web servers, and legacy systems are presented. Implementation considerations are described, including security, scalability, load balancing, fault tolerance, and management. Annotation c. Book News, Inc., Portland, OR (booknews.com)

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