Chapter 8: Web Servers

RQ1. Most electronic commerce Web sites use three- tier client / server architecture. In about 100 words, explain why they do and briefly describe what happens in the third tier of most electronic commerce Web sites.

The three tier architecture is needed to support dynamic websites and to process transactions. In most cases the third tier consists of databases and software applications which interact with the web server. The web server can extract the information from the database in order to produce dynamic websites. The third tier also helps with web catalog websites by responding to customer requests. For example, if a customer wanted more information on a product, the third tier is what allows the web server to search and retrieve the requested information from a database. Other than responding to requests, it also processes and responds to transactions by interacting with applications such as checkout software and databases consisting of pricing and “order complete” responses, which is important in ecommerce operations.

RQ3. Beginning with the links provided in the Online Companion, locate more information about two of the three Web servers discussed in the chapter: Apache, Microsoft IIS, and Sun JSWS. Write approximately 100 words about each of the two servers you choose. Include descriptions of three features for each Web server and indicate the computer platforms and operating systems on which each runs.

Apache is an open source web server created and maintained by a community of developers. It is the most common web server used online today. It is cross-platform compatible, supporting many of today’s operating systems such as Microsoft Windows, Mac OS X, Unix, and Linux. Apache also has a variety of features such as modular programming, DBM database implementation, customized error responses, as well as authentication and authorization set up.

Following Apache as the second most used web server is Microsoft IIS. This web server was created by Microsoft Windows specifically for Windows operating system. Unlike Apache, IIS is a paid service. It is a modular architecture with features such as ASP.NET and PHP support, integrated media platform, and centralized web farm.

RQ4. In one paragraph, outline the main differences between a typical desktop PC and a computer that would be suitable to use as a Web server for a small Web site.

A desktop PC is an individual-based computer used for personal activities such as browsing the internet, word processing, and media downloads. However, a web server is used on an upscale level by responding to client requests and delivering content to the internet. In order for web servers to take on these tasks, they have high-capacity memory and hard disk drives as well as faster, also multiple processers unlike PCs, which usually have one processor. Since web servers consist of these high-capacity elements, they are typically much larger and more expensive compared to  a desktop PC.

E2. You created a Web site for International Paper Products and Pulp, complete with links to other pages on your site and to pages on the Internet. Bob Pardee, your supervisor, wants you to check periodically that the links on the corporate site are still valid. Instead of purchasing and installing a link- checking program, you decide to investigate online link check-ers ( Web sites that allow you to enter a Web site’s root or home address and then check all the links that emanate from that site). Use W3C Link Check or Elsop LinkScan Quick Check to check the links on any site of your choice. Print a few pages of the report and be prepared to turn them in to your instructor. Be patient. The program can take some time to complete its work— especially on a Web page that has a large number of links.

In using the W3C Link Checker, I checked out www.smashingmagazine.com. The results showed that 26 links were not checked due to the robots exclusion rules. Meaning, the link was instructed by its web owner to disallow a check with robots.txt files.  Of the links that were checked, 7 links were broken links. This meant that they were missing characters in the URI in order to properly link. However, only 1 link was completely disabled due to a server side problem.