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Chapter 6

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Chapter 6

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  1. Chapter 6 Servers for E-Business

  2. Learning Objectives • Identify Components of an e-commerce platform • Select appropriate platforms for various situations. • Distinguish between critical and non-essential features of an e-commerce architecture. • List the components necessary for front-end and back-end of e-commerce transaction systems • Elicit the steps involved in establishing an e-commerce web site.

  3. Overview • Platform = Hardware + basic software required to run the computer. • Functions of a computer: • 1. Interface logic, • 2. Business application, • 3. Database and • 4. Display.

  4. Computing architecture Shift from: Centralized mainframe computing To: Distributed processing of clients and server Two-tier architecture: • Server, at the back end, • manages the essential functions like disk drives, • printers, network traffic and some applications. • Clients’ computers are at the user’s end, mainly personal computers, which run applications. They display data in text mode or graphical user interface. Multi-tier architecture: • Additional layers of computer servers have been added between the client and the server in the • Network.

  5. Phases of e-commerce architecture • First step: Placing the company’s information about products, prices, promotional schemes etc. on the web using a web server. • Second step: Receiving orders, managing inventory and collecting invoices. • Third step: Redesigning business process and supply chain in order to take full advantage of the technology. (Most challenging part as multiple components on multiple platforms have to be integrated). Achieved through Enterprise Resource Planning, Supply Chain Management and Customer Relationship Management.

  6. Basic e-commerce architecture

  7. Overview of computing Platforms • In the 1960s –Mainframe computing, centralized operations • Next, mini computers • 1980s – Client/Server architecture • Presently – heterogeneous Internet platform.

  8. Host-Based Platform • Centralized computing (one main server and many dummy terminals) • A single powerful computer server performs all the important functions. • Dummy computer terminals are at the other end, used for requesting a task or displaying results. • No processing is done at the dummy terminals. Only display is done here. • A database engine on the server provides shared data processing functions to all other applications. • Jobs are executed in batches. • Often, Front-end processor (FEP) is inserted between the two computers for connection and authorization services. 

  9. Client/Server Platform • Distributed computing (between one server and many clients). • In a traditional C/S system, the server performs only database function, while the client carries out the other three. • Fat client- display + interface logic, business application, significant amount of database processing. • Thin client- display + interface logic only

  10. Host Vs Client server systems.

  11. Differences between a host-based system and a C/S system • Client in a C/S system is a much powerful computer, usually a personal computer or computer workstation. • Client performs larger amount of functions. • The interface in C/S system through graphical user interface. • Depending on the application, the network capacity may be high or low.

  12. Technologies used on the local area networks include • Communication protocols: Transmission Control Protocol/ Internet Protocol (TCP/IP), Novell network protocol (SPX/IPX), Sequenced Package Exchange (SPX). • TCP/IP - a suite of communications protocols used to connect hosts on the Internet. • In-built into UNIX operating systems, SUN Solaris and Linux.

  13. World Wide Web Platform • WWW - a subset of wide area network. • Private or leased lines for implementing C/S system in a wide area network. • WWW is a vast distributed network of millions of servers where information is stored and which can be accessed and retrieved from other computers. • Language used for web pages – HTML (Hyper Text Markup Language) • TCP/IP followed for sharing and sending of data from the web servers to the browsers at the client’s end.

  14. WWW as an special case of C/S system • a n-tier distributed C/S system. • Web servers – dedicated machines acting as repositories for web pages. Web servers consist of hardware, O.S., web server software.. • At the client’s end, the software required to view the web pages on personal computer is called a browser. • Browsers – Netscape Navigator, Microsoft Internet Explorer, and Opera Browser, and mobile micro-browser.

  15. Internet mechanism • In WWW, any web server on any platform can interact with any browser running on any client machine connected through the Internet. • Linking the clients and server through dial-up connection, a privately leased line, digital subscriber line (DSL) or cable modem. • Access to the internet provided by Internet Service Providers like AOL, CompuServe, Prodigy or Telephone companies.

  16. Internet – fig 6-4

  17. Components of an e-commerce website 1. Informational website hosted on a web server on the company’s side 2. Web server on the visitor’s side 3. Access to e-mail for both the business and the client 4. the core editing/development tools associated with the platform.

  18. Fig 6-5 heterogeneous system.

  19. Additional functionalities of the website • Secure transactions using sophisticated software and hardware. • Links to back-end processing. • Links to external credit-checking and payment processing centers. • Delivery mechanism linking to the warehouse and shipping center.

  20. Complex e-commerce architecture

  21. Enterprise Resource Planning (ERP), Supply Chain Management (SCM), Customer Relationship Mgmt (CRM) provide competitive advantage to a firm vis a vis its competitors today.

  22. Fig 6-7Integrated e-business

  23. Components of E-commerce • Clients (with access to internet) • Internet • Routing devices at the boundary of the enterprise. • Extra devices to defend the perimeter against potential hackers. • Web server / commerce server • Application servers (in advanced systems) • Back-end transactional software (includes TP monitors, database management system and data warehouse).

  24. TP monitor • A program that monitors a transaction as it passes from one stage in a process to another. • It ensures that a transaction is completed successfully, or roll-back occurs, partial transactions are prevented. • TP is important in three-tier architectures that employ load balancing. • TP coordinates ERP, SCM and CRM.

  25. Web Browsers • Not all browsers support all web functionalities. • Originally Lynx was developed to display limited text. • Later, graphics was added. • Later iterations, a range of functionalities added, at the cost of computing resources and slower download.

  26. Major players in the browser market • Microsoft Internet Explorer (I.E.) and Netscape Navigator. • I.E. is more integrated with desktop operating system (mainly Windows), which is also a Microsoft product. • Netscape did not have a new product release between 1998 and 2000 and lost the number one position, which it held only three years ago to I.E. • I.E now claims more than 3/4th of the market. • Both are freely available for the end user.

  27. Microsoft Internet Explorer • Browser for display of web pages. • NetMeeting for collaboration • FrontPage Express for building Web pages. • Outlook Express for fully functional e-mail. • Supports FTP, Gopher, NNTP, JavaScript, ActiveX controls etc. • Java applets can be executed in version 5.x • I.E. 6.0 strongly supports VBScript

  28. Netscape Communicator • Netscape Navigator browser • Netscape Messenger (fully configurable e-mail client) • Netscape Composer (HTML editor) • Netscape Conference (for telephony interface) • Collabra discussion (for news groups) • Netcaster (for push technology) • Add-ins compatibility. • Java applets can be executed. • Netscape 6.x based on Mozilla (an open-source code) supports XML, though less stable.

  29. Other Browsers -Opera software • Optimizes space and speed. • Strict adherence to HTML standards • Sophisticated and speedy web-browsing with news and e-mail • Secure 128-bit SSL encryption. • Ideal for older machines and mobile computing with less available memory or disk space. • Soon the BeOS, Linux and Mac versions will also be available. • Freely available for download (in advertising mode) .

  30. HotJava • Java web browser from SUN • has small requirements and is designed to work on a variety of devices. • Not widely used

  31. Microbrowser • Wireless devices are constrained computing device with limited CPU, memory, battery life, and simple user interface; • wireless networks are restricted with low bandwith, high latency, and unpredictable availability and stability. • wireless subscribers have different needs and desires than desktop, or even laptop Internet users • WAP (Wireless Application Protocol) specification was developed to address the technical requirements and market issues unique to the wireless environment.

  32. Microbrowser • e.g. OpenTV, 4thpass, Nokia, PIXO…

  33. Mozilla • An open source project from Mozilla.org • A modular web browser, designed for standards compliance, performance and portability • Platform-independent • DocZilla- the latest project with enhanced support for XML and SGML by Finnish company CiTEC.

  34. Web Servers • A Web Server is a computer and associated software that is attached full-time to the internet. • The main software component is HTTP (HyperText Transfer Protocol) server, to process http requests. • Called httpd in UNIX and https in Microsoft Windows NT/2000.

  35. Constraints in selecting a Web server in an e-commerce project • Legacy software • Back office • Network • Administrator preferences • Web development skills of the staff

  36. Selecting a web server • Performance – minimum wait time for downloading • Development – where initial content can be developed and maintenance is not overly difficult. • Security – different levels of access rights to the users. • Multiple types of CPU, hardware and operating system should be supported. • Multi- platform solution – for longevity of the system without being tied to one particular CSP. • Clustering capabilities and automatic fail-over. • Stability and reliability.

  37. Functionality Checklist High performance HTTP engine • Connections per second or requests per second • Bytes per second • Round trip or response time • Errors • Functional compliance with HTTP version 1.1 or later. • Scalability of the architecture • Integration of clustering for fault-tolerance, load balancing and reliability

  38. Functionality Checklist contd.. Interface to the back end applications • Common gateway interface (CGI) • Cross platform interoperability • Java servlets and Java server pages • Open database connectivity (ODBC) • Remote method invocation (RMI)

  39. Functionality Checklist contd.. • Publishing capability • Management and administration • Availability of server for lengthy operations without interruptions • Ability of the web server to add functionality and to control the website’s content. • Security

  40. Web server and supportedplatforms

  41. Management issues in selecting a web server • Product feature set, current availability and the likely product evolution path. • Security (trade-in with high performance speed) • Built-in database connectivity and the availability of application development tools. • Manufacturer’s reputation, quality of technical support, prior experience with a particular manufacturer. • Purchase price, licensing and maintenance cost.

  42. Present web server market • Apache – 60 % of market share • MS Internet Information Server – 19 % • Netscape Communications Enterprise server (now iPlanet Enterprise Server) – 6 %.

  43. Apache Web Server • From www.apache.org • Available for free • Highly reliable and stable • Available for many platforms, in both binary and source code format • Since, it is open-source, bug-fixes are rapid and timely. • Demerits: Production version of server is not very user friendly, textual user interface. • Comanche (Configuration Manager for Apache) is an effort to have GUI for users, across various platforms.

  44. Microsoft Internet Information Server • From Microsoft a leading supplier of IT. • Distributed as a free component with NT server, tuned for performance on the Intel platform. • Personal Web Server (PWS) for small scale personal use on Windows 95 and 98. • IIS runs on a single platform (Intel processors on Windows NT OS). • Many add-ins available (database access tools, e-mails, security etc.) • Serious security questions

  45. IIS and Management console

  46. iPlanet Enterprise Server • From Netscape Communications (part of AOL now) • The Netscape Enterprise administrative console is intuitive to use, manage and configure. • Supports a range of platforms including Sun Solaris and Windows NT. • Highly stable, seldom requires re-booting. • Comparable to the other two dominant servers in the market. • Configure through Web User Interface (WUI). • WUI can be used to set up the server with I.E. or Netscape Navigator browser. • Supports Java applets.

  47. IBM Lotus Domino Server • From the stable of IBM. • Now being supplanted by IBM HTTP Server powered by Apache. • Offers integrated messaging and web application software platform for growing companies seeking improved customer responsiveness and streamlined business processes.

  48. Monitoring Web Server Performance • Overall network traffic • Performance of web server software and platforms. • The load generator (clients) • Workloads • Measurement and metrics

  49. Performance Planning and Monitoring Tools • Analysis of logs of active servers • Instrumentation of network • Server operating systems • Web software • Laboratory testing (benchmark)

  50. Sample Monitoring Tools • Webstone from Mindcraft • WebBench 3.0 by Ziff Davis • SPECweb96 from Standard Performance Evaluation Corporation • Web Capacity Analysis Tool (WCAT) and InetLoad from Microsoft • WebSizr and WebCorder from Technovations