E-Business Technology : Web-Based Tools for Electronic Commerce Mr. Seree Chinoom Department of Computer Science Burapha University E-mail : seree@buu.ac.th Learning Objectives Computer that support Web Servers Measuring the performance of Web server hardware Fundamental duties of a Web server The way that individual computers are combined to provide large-scale Web service Web server software, including Apache, Microsoft Internet Information Server, and Netscape Enterprise Server Advanced Web server tools Page Delivery Hypertext Transfer Protocol (HTTP) is the set of rules for delivering Web pages over the Internet HTTP uses the client/server model The combination of the protocol name and the domain name is called a uniform resource locator (URL). SMTP, POP, MIME, and IMAP E-mail sent across the Internet must also be formatted to a common set of rules, otherwise e-mail created by one company (o Web site) could not be read by a person at another company. Simple Mail Transfer Protocol (SMTP) specifies the exact format of a mail message and describes how mail is to be administered at the Internet and network level.
P, POP, MIME, and IMAP t.) An e-mail program running on a user s computer can request mail from the company s main e-mail computer using the Post Office Protocol (POP). Multipurpose Internet Mail Extensions (MIME) allow the user to attach binary files to e-mail. The Interactive Mail Access Protocol (IMAP) performs additional features. Internet Applications Electronic Mail E-mail is the most popular form of business communication surpassing the telephone, conventional mail, and fax in volume. One benefit is the ability to send documents and other information as attachments. The drawbacks of email include such things as Spam (or bulk mail) and computer virus delivered to your computer as email attachments. 5 rnet Applications (Email POP) Internet Application (Email IMAP)
rnet Applications (Telnet) Internet Applications (Telnet) Telnet Telnet is an application that allows you to log on to a remote computer that is attached to the Internet. It allows the user to run software that doesn t have a Web interface on a remote computer. As more companies place information on Web pages (accessible through any Web browser), the use of Telnet will continue to decrease. 9 rnet Applications (FTP) Internet Applications (FTP) FTP File Transfer Protocol (FTP) defines the formats used to transfer files between TCP/IP-connected computers. FTP transfers both binary data and ASCII text. Full privilege FTP allows remote uploading and downloading of files. Anonymous FTP allows you to log on to a remote computer as a guest.
kup Languages and the Web Web pages are marked with tags to indicate the display and formatting of page elements. SGML is a meta language, which is a language that can be used to define other languages. HTML and XML are both derivatives of SGML Standard Generalized Markup Language SGML offers a system of marking up documents that is independent of any software application. Advantages of SGML include its long-term viability, it is nonproprietary and platformindependent, and it supports user-defined tags and architectures. Disadvantages of SGML include a costly and complicated set up, expensive tools, creating document-type definitions that are time consuming, and extensive learning time. 13 ertext Markup Language HTML is a simplified subset of SGML that includes tags defining the format and style of text elements in a document. HTML is an instance of one particular SGML document type Document Type Definition (DTD). HTML now includes tags for tables, frames, and other features that help Web designers create more complex page layouts. Extensible Markup Language Unlike HTML, XML uses markup tags to describe the meaning of the text rather than its display characteristics. XML uses paired start and stop tags in much the same way as database software defines record structure. An XML document can be embedded within an HTML document. XML allows a user to extend the language by creating their own tags.
kup Languages and the Web Markup Languages and the Web 17 L Tags HTML Tags An HTML document contains both document text and elements. Tags are codes that are used to define where an HTML element starts and (if necessary) where it ends. In an HTML document, each tag is enclosed in brackets (<>). A two-sided tag set has an opening tag and a closing tag.
L Tags HTML Links Hyperlinks are bits of text that connect the current document to: Another location in the same document Another document on the same host machine Another document on the Internet Hyperlinks are created using the HTML anchor tag. Two popular link structures are: Linear hyperlink structure Hierarchical hyperlink structure 21 pting Language and Style Sheet abilities Web designers can use the OBJECT tag to embed scripting language codes in HTML pages (this is also called client-side scripting). Scripts can execute program on computers that display those pages. Cascading Style Sheet (CSS) let designers define formatting styles that can be reapplied to multiple Web pages. HTML Editors HTML documents can be created in any general purpose text editor or word processor. Sophisticated editors can create full-scale, commercial-grade Web sites with database access, graphics, fill-in forms, and display th Web page along with the HTML code. Microsoft FrontPage and Macromedia Dreamweaver are examples of Web site builders.
L Editors Web Server Hardware and Performance Evaluation Today a Web site may be the first plac 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. 25 es of Web Sites An important first step in planning a Web server is to determine what the company wants to accomplish with the server. The company must estimate how many visitors will be connecting to the Web site and what types of files will be delivered through the site. Companies create Web sites in a wide variety of forms including simple development sites, intranets, information-only sites for customers, business-tobusiness portals, storefronts, or content-delivery. Development Sites The simplest Web site and the least costly to implement is a development site. A development site can reside on an existing PC and can be developed with low-cost Web site building tools, such as Microsoft FrontPage or Macromedia Dreamweaver. Testers can access the site through their PCs on the existing LAN.
anets Corporate intranets house internal memos, corporate policy handbooks, expense account worksheets, budgets, newsletters, and a variety of other corporate documents. Intranets are shielded from the Internet, they do not require additional security software to protect them against threats from outside the company. Transaction-Processing Sites Transaction-processing sites, such as business-to-business and business-toconsumer electronic commerce sites must be available 24 hours a day, seven days a week that is, they must be high reliability servers. Transaction-processing sites must also have spare server computers to handles high traff volumes. Transaction-processing sites must also run security software. 29 tent Delivery Sites Content delivery sites, such as The Wall Street Journal, The New York Times, and C- Net, sell and deliver content, such as news, histories, summaries, and other digital information. Content must be presented rapidly on the visitor s screen. Visitors must be able to locate articles quickly with a fast and precise search engine. Web Hosting Choices The company must decide whether to run servers in-house or through third-party Web and e-commerce providers. Companies should consider: Scalability of e-commerce Bandwidth of the Web site A local third-party ISP Contact Web Host Guild (WHG) for help.
Hosting Choices Web Hosting Choices When making Web server hosting decisions, company should ask whether the hardware, or platform and software combination, can b upgraded when the traffic on its site increases. Using a service provider s shared or dedicated hosting services instead of buildin an in-house server or using a co-location service means that the staffing burden shifts from the company to the Web host. 33 Hosting Choices Operating Systems for Web Servers Hardware decisions go hand in hand with operating system and application server software choices. Companies should consider: Speed A fast server is better than a slower one Internal and external traffic to occur on the serve Scalability of the server hardware
Reports on Various Web Servers dcraft.com) Test Reports on Various Web Servers (Mindcraft.com) 37 ding a Scalable E-commerce Systems Three layers in E-commerce systems: Web server layer Middle-tier layer Backend layer An application server is a middle-tier software and hardware combination that lies between the Internet and a corporate backend server. Web Server Performance Evaluation Benchmarking is a form of testing used to compare the performance of hardware and software. Hardware and operating systems are key areas for benchmarking. The speed of its connection can affect a Web server s performance. Throughput and response time can be used to measure a server s Web page delivery capability.
Server Benchmark Software Web server benchmark software types are listed below: NetBench ServerBench SPEC SFS97 SPECweb99 WCAT WebBench WebStone Desirable Features of Web Servers Web servers are located on the Interne or intranets, usually behind firewalls. The duties and features of Web servers differ depending on whether they are publicly accessible. Web server software features depend on the software package being used. 41 e Capabilities The most fundamental duty of a Web server is to process and respond to Web client requests that are sent using the HTTP protocol. For dynamic pages, the server uses an architecture with three or more tiers that invokes other programs. Indexing and Searching Search engine and indexing programs are important elements of many Web servers. Search engines, or search tools, search eithe a specific site or the entire Web for requeste documents. An indexing program can provide full-text indexing that generates an index for all documents stored on a server.
a Analysis Data Analysis Web servers can capture visitor information, including data about who is visiting a Web site, how long the visitor s Web browser viewed the site, the date and time of each visit, and which pages were displayed. Two of the most popular Web log file analysis programs are the Analog Web server log file analyzer and the WebTrends Web server log file analyzer. 45 Management Tools FrontPage has some site management capabilities. HomeSite is a site management tool that validates graphic, computes pagedownload times for modem connection, validates links, and validates HTML codes. Site Management Tools Application construction uses Web editors an extensions to produce Web pages. Some Web development systems provide simple tools to create Web pages. Some tools can be used to create dynamic features without the need to know CGI or us API coding.
Checking A link checking examines each page on the site and reports on any URLs that are broken, that seem to be broken, or that are in some way incorrect. An orphan file is a file on a Web site that is not linked to any page. Other important site management features include scripts checking an HTML validation. A dead link, when clicked, displays an error message rather than a Web page. Link Checking Free link-checking and Web site validation programs, such as Elsop Linkscan, can be launched by entering the address of a Web site s home page and checking a few boxes. Commercial site checkers, such as Big Brothe software from Watchfire, produce more comprehensive results and more detailed sit analyses than do the free products. 49 Checking Remote Server Administration With remote server administration, a Web si administration can control a Web site from any Internet-connected computer. Although all Web sites provide administrative controls, it is convenient for an administrato to be able to fix the server from wherever he or she happens to be.
ote Server Administration Tool Dynamic Content Dynamic content is nonstatic information constructed in response to a Web client s request. Using Open DataBase Connectivity (ODBC), the Web server can assemble information from disparate database systems. Active server pages (ASP) is a server-side scripting mechanism to build dynamics sites and Web applications. 53 amic Content Most Web sites today provide dynamic Web pages using an approach called server-side scripting. In server-side scripting, programs running on the Web server create Web pages before sending them back to the requesting Web clients as parts of response messages. Microsoft uses Active server pages (ASP). Sun uses Java server pages (JSP). Apache developed Hypertext Preprocessor (PHP). 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 iplanet (Netscape) Enterprise Server
che 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 HTTP Server 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. 57 che HTTP Server Microsoft Internet Information Server 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.
rosoft Internet Information Server iplanet Enterprise Server (Netscape) 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. 61 net Enterprise Server Sun One Software Page
ONE Web Server Sun ONE Web Server Build multiplatform,e-commerce web application, Java Servlet and Java Server Pages Sun ONE Active Server Page Deploy Web site and Application based on Active Server Page (ASP) using the Apache, Sun ONE and Zeus Web servers Sun ONE Web Proxy Server Acts as a traffic network manager by collecting data from the network, determining where the data should be routed, and distributing it appropriately Determining Web Server Hardware and Software Information You can determine the type of hardware and software most Web sites are running by visiting Netcraft. Netcraft software examines the designated Web site and returns both the Web server hardware and software information. 65 rmining Web Server Hardware Software Information 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 switche is called server architecture.
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 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 loadbalancing systems. 69 d-balancing Systems Load-Balancing System Architecture A load-balancing switch is a piece of network hardware that monitors the workloads of the servers attached 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.
plex Load-Balancing Search Engines A search engine is a special kind of Web pag 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 hierarchica categories. Search engines contain three major parts: spider, index, and utility. 73 lligent Agents Software agents have been in use for a number of years. An intelligent agent is a program that performs functions, such as information gathering, information filtering, or mediation running, in the background on behalf of a person or entity. Research reveals that software agents will become extremely important in the electronic commerce field sooner than later. Intelligent Agents Because software agents are always running in the background they can help reduce the workload that people normally take on in locating, thinking about, negotiating, and purchasing goods and services. Examples of agent systems include Bes Web and MySimon.