Distributed Processing. The Internet and the New Information Technology Infrastructure. Reasons for Implementing Distributed Systems

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1 Distributed Processing The Internet and the New Information Technology Infrastructure Distributed Processing can be defined as a system in which both computer processing and data occur at more than one site; application programs are run at more than one site. Distributed processing is associated with all type of networks: including WAN, LAN, PBX, and even the Internet. M7011 Peter Lo M7011 Peter Lo Reasons for Implementing Distributed Systems Improved Response Time Reduced Costs Improve Accuracy Reduced Mainframe Costs Smoother Growth Increased Reliability Resource Sharing Increased User Satisfaction Improved Response Time When data and processing power are located closed to users, response time improves. M7011 Peter Lo M7011 Peter Lo

2 Reduced Costs When branch office can key in, edit and process much of the data locally, those transmission costs are substantially reduced. Improve Accuracy A branch department clerk entering branch data is likely to know more about the data and therefore spot errors more frequently. M7011 Peter Lo M7011 Peter Lo Reduced Mainframe Costs Collections of microprocessors offer a better price/ performance ratio than large mainframes Smoother Growth If a new small system is added at a remote site, only a remote site may be affected. M7011 Peter Lo M7011 Peter Lo

3 Increased Reliability In a distributed system, failure of one processor disrupts only the operations dependent on that particular processor. Resource Sharing Computers have different functional capabilities yet may need to share resources Client / server Data gathering / data processing M7011 Peter Lo M7011 Peter Lo Increased User Satisfaction Users may welcome more control over computing power so that they can reduce the time they wait for their tasks to be addressed. Distributed Processing Concerns for Managers Lack of Professional MIS Staff Standardization Documentation Data Loss Security Data Consistency System Maintenance M7011 Peter Lo M7011 Peter Lo

4 Lack of Professional MIS Staff Small branch sites on the distributed network may be run by personnel with little or no training or experience with computing systems. Standardization Without control, local units might acquire incompatible equipment and software, and the system will be unable to provide integrated computing resources to everyone on the network. M7011 Peter Lo M7011 Peter Lo Documentation Application-program development at remote site increases the risk that these programs may not be fully documented. Data Loss Without some form of central control or enforcement of archiving procedures, inexperienced users of minicomputers and microcomputers at remote sites may treat archiving of data too casually, and data loss is like to result. M7011 Peter Lo M7011 Peter Lo

5 Security Without some form of organization-wide control, security procedures for confidential data or small, remote computing sites may easily become lax [slack, careless] or they may not exist at all. Data Consistency Without careful planning, monitoring and controls, the situation invites increased risks of data redundancy and therefore data inconsistency. M7011 Peter Lo M7011 Peter Lo System Maintenance Large, centralized data centers have trained professionals who are experienced in program and system maintenance. It may be very difficult to provide system maintenance promptly at every distributed site. M7011 Peter Lo An Effective Distributed Processing System Distributed processing systems must be managed very carefully to be effective. Some form of organization-wide monitoring, supervision, training, and control is necessary to ensure the system does not get out of hand. It should be easy to use, User should not have to be concerned with where the data are or where the processing is occurring: data must exhibit location transparency. It should also guard against loss of data consistency. The software and procedures should provide automatic system-wide updates. Automatic system wide updates through update transparency. M7011 Peter Lo

6 Centralized Databases In a centralized system, the computer system and the database of an organization are both found at one location. Databases in this setting are called Centralized Databases. Distributed Databases Organizations that need to decentralize their computer processing may also need to decentralized their database. When computing databases are scattered rather than centralized, they are called Distributed Database Systems. M7011 Peter Lo M7011 Peter Lo Distributed Databases There are two ways to distribute a database Replicated Databases Partitioned Databases Replicated Databases It provide duplicates of all data at all sites. If every location must have frequent access to the same data, replication of database may be recommended. It is very expensive in terms of computer system resources, and it can be difficult and costly to maintain consistency for each data element. It does provide some measure of security by providing duplicates of the database in case of failure at one location. M7011 Peter Lo M7011 Peter Lo

7 Partitioned Databases The database may be divided into segments that are appropriate for certain locations and distributed only to those locations. This approach is called Partitioned Database. The database may be partitioned along functional lines; e.g. financial, marketing, and administrative data are kept at corporate headquarters, and relevant production and personnel data are kept at each manufacturing plant and office site. Partitioning may also be achieved along geographical lines. Advantages of Distributed Databases They usually reduce costs for an organization because they reduce costs of transferring data between remote sites and organization s headquarters They may also provide organization with faster response times for filling orders, answering customer requests, or providing managers with information. M7011 Peter Lo M7011 Peter Lo Disadvantages of Distributed Databases They compound problems with control and security for the database; increase data redundancy and the resulting data inconsistency; require and increase the need for more computer resources. Unless the distribution of a database is done very carefully, many of the advantages of having a database in the first place can be lost. Client/Server Computing The basic notion of a client/server computing system is the application processing is divided between a client, which is typically a PC; and a server, which may be on a LAN, a minicomputer or a mainframe. The client process run on the PC and make requests to the server processes. Typically components of client/server computing are a relational database, a powerful server or servers, personal computer workstations, network and client software for the workstations. Application processing is on the client computer. Server computers store the database and data. M7011 Peter Lo M7011 Peter Lo

8 SQL Server A common application of client/server computing is the use of special relation database software called Structured Query Language or a SQL server. The SQL server computer usually devotes all its energies to managing the database software and does not handle other network tasks. The SQL server processes the request at the server and sends only those records that meet the selection parameters. Downsizing Organizations with high maintenance costs on existing mainframe computer hardware and software are increasing downsizing to LAN-based, client/server computing systems from older, preexisting, legacy mainframe-based information systems. M7011 Peter Lo M7011 Peter Lo Internet Communications How did the Internet Originate? Many people describe the Internet as a network of networks or a relatively ungoverned aggregation of computers and computer networks located throughout the world. In fact, the Internet provides yet another example of client/server computing. The Internet allows you to connect your PC (client) to computers (server) located at sites around the world to use their services. The Internet began in the 1960s as ARPANET (Advanced Research Projects Agency Network) to connect research, military, and government network. The organization (or company) providing access to the Internet is known as the Internet Service Provider (ISP). Goal: To allow scientists at different locations to share information ARPANET Networking project by Pentagon s Advanced Research Projects Agency (ARPA) Goal: To function if part of network were disabled Became functional September 1969 M7011 Peter Lo M7011 Peter Lo

9 Who provides the Internet s Structure Today? How has the Internet grown? Today Networks from corporations, commercial firms, and other companies Telephone companies Cable companies More than 100 million host nodes 1984 More than 1,000 host nodes Satellite companies Government 1969 Four host nodes M7011 Peter Lo M7011 Peter Lo Who Controls the Internet? Nobody; it is public, cooperative, and an independent network Several organizations set standards 1 Regional ISP 2 National ISP 3 OSP (Ex. AOL) What are ways to Access the Internet? World Wide Web Consortium (W3C) Oversees research, sets standards and guidelines Tim Berners-Lee, director Internet2 (I2) Internet-related research and development project Develops and tests advanced Internet 4 Wireless Internet Service Provider M7011 Peter Lo 2005 technologies 35 M7011 Peter Lo 2005long-distance local toll-free local 36 call call call call local call local call 4

10 How can you Connect to the Internet? Very high-speed connection Digital Very subscriber high-speed line (DSL) connection and cable modem Dial-up access What are three parts of an Internet connection? Digital subscriber line (DSL) and cable modem Client Backbone Server Dial-up access M7011 Peter Lo M7011 Peter Lo How might data travel the Internet using a telephone line connection? 1: Request data from the a server on Internet. Regional 2: Modem converts digital Step 3 ISP signals to analog signals. 3: Step 5 Data travels through Step 1 telephone lines to a Step 2 Step 4 local ISP. 4: Data passes National through routers. ISP 5: Regional ISP uses leased lines to send data to a national ISP. Step 6 Local ISP 6: National ISP routes Internet data across the backbone country. Step 8 7: National ISP passes data to local ISP. Step 7 8: Server sends data back M7011 to you. Peter Lo 2005 National ISP 39 T1: Mbps T3: Mbps How the Internet Works Internet service provider (ISP) Network service provider (NSP) Phone company Backbone network Cable company Phone company OC3: Mbps OC12: 622 Mbps Dial-up: Kbps ISDN: 128 Kbps DSL: 256 Kbps - 6 Mbps Company Individual Cable: 1.5 Mbps Web site M7011 Peter Lo

11 Internet Features Internet Features include magazines, databases, bulletin boards, shopping malls, electronic mail anything and everything. Sample Internet Features Instant Messaging Chat Room / Discussion Groups Internet Telephony and Desktop Conferencing Collaboration Groupware Searching Information Electronic Mail Transferring Files Remote Control M7011 Peter Lo M7011 Peter Lo Instant Messaging (IM) Chat Room / Discussion Groups 1: Login to the IM server 2: Server checks if any established friends, family, or co-workers, called buddies, are online Step 1 Step 2 Area on the Web where users conduct written discussions about a particular subject Also called Threaded Discussion 3: Send instant messages to online buddy IM server 4: Instant message travels through messaging server and then to online buddy messaging server Step 3 Step 4 M7011 Peter Lo M7011 Peter Lo

12 Internet Telephony and Desktop Conferencing Enables you to talk to other people over the Internet such as Voice Over Internet Phone (VoIP) M7011 Peter Lo Collaboration Working with other users connected to a server You can conduct online meetings Allows you to share documents with others in real time Microsoft s NetMeeting allows collaboration everyone in online meeting can see and edit document chat room NetMeeting window M7011 Peter Lo Groupware Software application that helps groups of people work together on projects and share information over a network Lotus Notes Microsoft Exchange Searching Information Search engines enable you to do key word searches M7011 Peter Lo M7011 Peter Lo

13 Electronic Mail Transferring Files File Transfer Protocol (FTP) using the Internet enables uploading new software and software patches. M7011 Peter Lo M7011 Peter Lo Remote Control Running programs at remote computers Telnet Log on to other computer M7011 Peter Lo M7011 Peter Lo

14 Gopher A tool that enables the user to locate information stored on Internet servers through a series of easyto-use, hierarchical menus. Internet Protocol (IP) address Number that uniquely identifies each computer or device connected to Internet IP address first part identifies network last part identifies specific computer M7011 Peter Lo M7011 Peter Lo Domain Name The unique name of a collection of computers connected to the Internet. Text version of IP address Example: peter@peter-lo.com (peter-lo.com is the domain name) IP address Domain name scsite.com What is a URL? Unique address for Web page located on Web server protocol domain name path M7011 Peter Lo M7011 Peter Lo

15 Arin.net Net Range Microsoft- Global-Net Domain Name System Registration Internet World ISP Real World Internic.org DNS Registration Microsoft Corporation One Microsoft Way Redmond, WA US Internet entities are anchored to the real world through the DNS registration and through their ISP. If they tell the truth! M7011 Peter Lo Portal Web Site Web site providing an initial point of entry to the Web. Offers a variety of Internet services from a single, convenient location Often called a Portal Yahoo! is a portal M7011 Peter Lo Push Technology Method of obtaining relevant information on networks by having a computer broadcast information directly to the user based on pre-specified interests. Multicasting Transmission of data to a selected group of recipients. Internet Commerce Web site containing adverting about a company and its products even a small organization can reach millions of potential customers in the world. However, advertising is not the only commercial venture on the Internet. Electronic Commerce (e-commerce) over the Internet being explored on a wide front by many organizations. For example: Electronic magazines Online banking Using the Internet to make reservations for hotels, airlines, and travel M7011 Peter Lo M7011 Peter Lo

16 Intranet Communications Intranet Communications Security By connecting the company network to the global Internet, the company also opens up itself to increased increase security problems (such as hacking, etc). To resolve these problems, some companies have chosen to use Internet technology within their organization. An Intranet can be briefly described as a private, intraorganization communication network using the Internet technology without connecting to the Internet. Intranet provides many of the same features and benefits of the Internet (such as , etc) while avoiding some of the costs and risks. Firewall Hardware & Software placed between an organization s internal network and an external network to prevent outsiders from invading private networks. M7011 Peter Lo M7011 Peter Lo Intranet Applications for E-Business Finance & Accounting Human Resources Sales & Marketing Manufacturing & Production Intranet Applications for E-Business: Finance & Accounting Internet can provide an integrated view of financial & accounting information on-line. M7011 Peter Lo M7011 Peter Lo

17 Intranet Applications for E-Business: Human Resources HR can use intranets for on-line publishing of corporate policy manuals, job postings and internal job transfers, company telephone directories, and training classes. Intranet Applications for E-Business: Sales & Marketing Oversee and coordinate the activities of the sales force. Sales staff can dial in for updates on pricing, promotions, rebates etc. M7011 Peter Lo M7011 Peter Lo Intranet Applications for E-Business: Manufacturing & Production Intranet can make manufacturing information more accessible to different parts of the organization, increasing precision and lowering costs. Extranet Communications While an intranet is confined to your own organization and the Internet is open to the world, an extranet lies somewhere between the Internet and an Intranet. An Extranet is an extended intranet accessible to selected group not open up to general public. A typical extranet allows connections between wide groups such as an organization s customers and suppliers. M7011 Peter Lo M7011 Peter Lo

18 Internet Benefits to Organizations Connectivity and Global Reach Reduced Communication Costs Lower Transaction Costs Reduced Agency Costs Interactivity, Flexibility, and Customization Accelerated Distribution of Knowledge Internet Business Models Virtual Storefront Marketplace Concentrator Information Brokers Transaction Brokers Electronic Clearinghouses Marketplace Concentrator Information Brokers Transaction Brokers Electronic Clearinghouses M7011 Peter Lo M7011 Peter Lo Internet Business Models: Virtual Storefront Sells physical goods or service on-line Internet Business Models: Marketplace Concentrator Concentrates information about products and services from multiple providers at one central point M7011 Peter Lo M7011 Peter Lo

19 Internet Business Models: Information Brokers Provide product, pricing and availability information Internet Business Models: Transaction Brokers Complete transaction. M7011 Peter Lo M7011 Peter Lo Internet Business Models: Electronic Clearinghouses Auction Internet Business Models: Reverse Auction Consumer submit a bid to multiple sellers to buy goods or services at a buyer-specified price. M7011 Peter Lo M7011 Peter Lo

20 Internet Business Models: Digital Product Delivery Sell digital products Internet Business Models: Content Provider Customer pay to access content M7011 Peter Lo M7011 Peter Lo Internet Business Models: On-line Service Provider Provide service and support for hardware and software users Disintermediation The removal of organizations or business process layers responsible for certain intermediary steps in a value chain. M7011 Peter Lo M7011 Peter Lo

21 Web Hosting Service Company maintaining large web servers to maintain the Web sites of fee-paying subscribers. Electronic Payment System The use of digital technologies such as electronic funds transfer, credit cards, smart cards and Internet-based payment systems to pay for products and services electronically. M7011 Peter Lo M7011 Peter Lo M-Commerce Internet access everywhere Cell phones PDAs Laptops Great potential Limited usability Better than voice? Cell Phones and Wireless Communication Wireless cells work by handing off the wireless connection to the next tower as the caller moves. Connections to multiple towers at one time enables the system to triangulate to get a fairly precise location of the cellular device--even when it is not in a call. Location knowledge will make it possible (although perhaps not desirable) to offer new business opportunities as people move into range. M7011 Peter Lo M7011 Peter Lo

22 Global Telecommunications Technical problems Multiple standards Language Developing nations Time zones Limits to space & waves Political complications Transborder data flows Taxes Privacy Accessibility Cultural issues What is an object? Management & control M7011 Peter Lo