Web Server Hardware and Software Chapter 8 Web Server Hardware and Software

Web Server Hardware and Performance Evaluation Today a Web site may be the first place customers go to conduct business with traditional companies, while electronic commerce sites have become the main business focus for many organizations. The two main ingredients in a Web server are its hardware and it Web server software.

Web Server Hardware and Performance Evaluation Most Web servers used for electronic commerce are designed to be servers. Run on computers that use one of the following operating systems: Microsoft Windows NT Server, Microsoft Windows 2000 Server Edition, Linux, or one of several UNIX-based operating systems - designed to handle multiple simultaneous users. Hardware and operating system platform - match the servers currently in use in the company. Scalability - as a business grows, the Web server should be able to expand to meet increased demand. Performance benchmarks - speed and efficiency with which static Web pages can be handled, time from request to performance, and maximum capacity for requests.

Desirable Features of Web Servers Primary function of a Web server = respond to a Web browser requests by serving static Web pages. Additional functions - site management, application construction, dynamic content, and electronic commerce functions. Security functions – important - especially for applications that include sensitive data. Searching capabilities that allow users to search a site - important - especially for large sites. Data analysis capabilities - important - allow site designers and administrators to track how the site is being used.

Dynamic Content Web server software also provides many supporting functions. Most significant - support for interactive Web pages. A standard HTML document is static, but a dynamic Web page responds interactively to user preferences and actions. This functionality can be provided through server-side includes, server scripting languages, and other development tools. Closely related to this functionality is the ability to query data located in a database, and to use this to create a dynamic Web page. The Web server might also provide utilities to simplify the process of loading pages onto the server and converting documents to HTML.

Web Server Software There are two distinct Web servers in the market: intranet servers and public Web servers. Three of the most popular Web server programs are: Apache HTTP Server Microsoft Internet Information Server Netscape Enterprise Server

Apache HTTP Server The Apache HTTP Server is free and performs efficiently. Apache runs on many operating systems and the hardware that supports them. Apache has a built-in search engine and HTML authoring tools and supports FTP. Apache can be managed from either a server console or a Web server. Apache supports Server Side Includes (SSI), Active server pages and Java Servlets.

Microsoft Internet Information Server (IIS) IIS comes bundled with Microsoft’s Windows NT Server and 2000 Server operating systems. IIS includes an integrated search engine. IIS supports FTP, permits administration from a remote browser. IIS combines HTML pages, ActiveX components, and scripts to produce dynamic pages.

Microsoft Internet Information Server (IIS)

iPlanet Enterprise Server The iPlanet enterprise server runs on such operating systems as AIX, Digital UNIX, HP-UX, Irix, Solaris, and Windows NT. iPlanet Web server provides a powerful development environment that supports development of Web-based applications that can run on the Internet, an intranet, or an extranet. iPlanet Web server’s management tools allow administrators to manage users and monitor server activity interactively.

iPlanet Enterprise Server

Server Architectures and Server Utilities Companies that operate more than one Web server must decide how to configure their servers to provide site visitors with the best service possible. The different ways that servers can be connected to each other and to related hardware, such as routers and switches, is called server architecture.

Web Server Architectures Large electronic commerce Web sites must deliver millions of individual Web pages every day. They must also process thousands of customer and vendor transactions each day. The large collection of servers that these sites have are called server farms.

Web Server Architectures One approach to Web server architecture is called a centralized architecture, which uses a few very large and very fast computers. Another approach is a decentralized architecture, which uses a large number of servers. Most large decentralized sites use load-balancing systems.

Load-Balancing Systems A load-balancing switch is a piece of network hardware that monitors the workloads of the servers attached to it and assigns incoming Web traffic to the server that has the most available capacity. In a simple load-balancing system, the traffic that enters the site from the Internet, encounters the load-balancing switch, which then directs the traffic to the Web server best able to handle the traffic.

Load-Balancing System Architecture

Complex Load-Balancing

Search Engines A search engine is a special kind of Web page software that finds other Web pages that match a word or phrase you entered. A Web directory is a listing of hyperlinks to Web pages that is organized into hierarchical categories. Search engines contain three major parts: spider, index, and utility.

Questions What is the purpose of benchmarking in the evaluation of Web server software? What are the differences between static and dynamic Web pages? What is the most popular Web server software? What are the three components of a search engine?

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