Web-Based Information Systems

Web-Based Information Systems Fall 2004 CMPUT 410: Internet and WWW Dr. Osmar R. Zaïane University of Alberta Web-Based Information Systems

Course Content • Introduction • Internet and WWW • Protocols • HTML and beyond • Animation & WWW • CGI & HTML Forms • Javascript • Databases & WWW • Dynamic Pages • Perl & Cookies • SGML / XML • CORBA & SOAP • Web Services • Search Engines • Recommender Syst. • Web Mining • Security Issues • Selected Topics Preliminaries Web-Based Information Systems

Objectives of Lecture 2 Internet and WWW • Get a brief overview of the history of the Internet and the different tools that exist on the Internet; • Understand the distinction between the Internet and the World-Wide Web. Web-Based Information Systems

Outline of Lecture 2 • The Memex machine: the dream will come true • Hypertext: linking new kinds of documents • The Internet: infallible information exchange • The World-Wide Web and the start of a new era • Web-based applications • Some terminology Web-Based Information Systems

When Did It All Start? • In 1945, Vannevar Bush wrote an article “As We May Think” describing a machine, Memex, containing human collective knowledge organized with “trails” linking materials of the same topic. • The article revolutionized information technology before even the existence of modern computers. Web-Based Information Systems

Where is the memex? • Memex is a hypothetical machine. • The information stored ought to be accessible. • We haven’t fulfilled the dream yet. • But much has been achieved in 50 years. Web-Based Information Systems

Hypertext-Hyperlink-Hypermedia • Following Memex idea, Ted Nelson developed the Xanadu project which aimed at placing the entire world’s literary corpus on-line. • Ted Nelson coined the term hypertext in 1965. A document is not contiguous but is a set of connected parts of documents. Hyperlinks are links that connect sub-documents. Hypermedia is a multimedia hypertext document, Web-Based Information Systems

ARPAnet • In the heart of the cold war, ARPA (Advanced Research Projects Agency) was created (1957). The purpose was to outrun the Russians in the race for mastering rocket launching. • In 1969, it was decided to link sensitive computer centres by a network in order to withstand a possible nuclear attack. The idea was to allow centres to communicate even after a centre is destroyed. (Bob Taylor’s idea) • It connected government labs, major research centres and universities. • It existed until 1988 and was officially dismantled in 1990. • Backbone Network speed: 64Kbits/second • Major achievements: • TCP/IP, Domain Name Service, e-mail (SMTP), FTP, Telnet... Web-Based Information Systems

NSFnet • DARPA, the Defense Advanced Research Projects Agency, still exists and the military have their own network but the original ARPAnet was integrated into the current Internet. • The National Science Foundation in the USA funded the NSFnet which was created in 1985. • Backbone Network speed: T1 (1.5mb/sec.) to T3 (45mb/sec.) • It originally connected 5 major universities with supercomputer centres, but rapidly included other universities, research centres and private companies. • Replaced ARPAnet as the backbone of Internet in 1990 Web-Based Information Systems

What about the Internet? • The Internet didn’t originate in the USA alone. • Other networks existed in North America and Europe and other places in the world. • BitNet, for instance, connected many research centres and universities. • Bridges connected these networks to create a larger international network: the Internet. • Late 90s: Internet2, funded by US universities, a sequel to NSFnet with new protocols. Web-Based Information Systems

CA net Year Speed USA equivalent Ca net 1990 1.5 mb/s NSFnet Ca net 2 1997 155 Mb/s Internet2 Ca net 3 1999 2.5 Gb/s Internet2 Abilene & vBSN projects Canada committed $110 million for Ca net4, a10 Gb/s optical network connecting research institutions across Canada. Web-Based Information Systems

Explosive Growth Web-Based Information Systems

Internet Timeline 1980 2000 1970 1975 1985 1990 1995 1969 ARPANET commissioned by DoD 1982 ARPANET transition to TCP/IP 1992 Veronica 1994 Harvest 1996 Internet phone 1998 Internet Tax Freedom Act 1974 TCP/IP 1979 USENET 1986 NSF-Net created 1990 ARPANET ceases to exist 1995 Java 1993 Mosaic 1995 VRML 1997 Wireless Internet access 1972 ARPANET demonstration 1985 FTP 1988 IRC 1990 Archie 1999 Internet2 NGI 1981 BITNET and CSNET come into being 1992 MBONE 1994 E-commerce 1986 NNTP 1991 Gopher 1998 Clever 1996 AltaVista 1971 FTP on NCP 1993 Crawlers 1999 RSVP 1983 ARPANET splits into ARPANET and MILNET 1994 Yahoo 1991 WAIS 1996 WebSQL 1973 First international connection (UK+Norway) 1993 W3C 1998 Google 1994 UCSTRI 1992 WWW in CERN 1997 WebOQL 1994 MLDB + WebQL 1991 Netfind 1993 Aliweb 1 1969 3 1973 11 1989 33 1991 49 1992 59 1993 81 1994 96 1995 134 1996 171 1997 # countries Year 4 1969 62 1974 213 1981 1,961 1985 313,000 1990 1,486,000 1993 6,642,000 1995 36,739,000 1998 # hosts Year Web-Based Information Systems

Advent of the World-Wide Web • In 1990, Tim Berners-Lee developed a on-line hypertext-based system to help researchers at CERN in Switzerland share information across a diverse computer network. • He came up with first versions of HTML (based on SGML) and the HTTP protocol. • HTTP and HTML catapulted the Internet to new heights. • The WWW revolutionized the use of the Internet thanks to a multimedia user friendly interface: a web browser. • Mosaic was developed in NCSA by students at the University of Illinois in 1993, among them Marc Andreessen who created Netscape in 1995. Web-Based Information Systems

The WWW is not alone • There are other tools on the Internet. They could be classified as: • Command Line. Ex: FTP (1971) • Menu-based. Ex: gopher (1991) • Search engine. Ex: WAIS (1991) • Hypermedia. Ex: WWW (1991) Web-Based Information Systems

Other Taxonomy of Internet Tools • Communication services • E-mail, newsgroups (usenet), telnet, internet relay chat (IRC), … • Information storage and exchange • FTP, Gopher, Alex, … • Information Indexing • Archie, Veronica, Wais, UCSTRI, Whois, … • Interactive Multimedia information delivery • WWW and its indexes. Web-Based Information Systems

Provides the information Requests the information Server Client Client-Server Architecture The World-Wide Web is an assortment of interconnected computers. In this context, computers provide data to other computers. Web-Based Information Systems

URL Request Response HTML page Client-Server Architecture HTTP Client Server Web-Based Information Systems

Request + Data Response Application Client-Server Architecture HTTP DB HTTP server Browser Javascript and Java CGI + Servlets (Perl and Java) Web-Based Information Systems

Request + Data Response Application / Application Communication – scenario 1 Application Identifying fields and variables Wrapper needed HTTP DB Application Parses the HTML page to extract the needed information HTTP server Wrapper needed No browser involved Web-Based Information Systems

XML request + Data Response Application / Application Communication – scenario 2: XML doc SOAP over HTTP Web Service DB Application parses XML with known DTD or schema XML doc HTTP server CORBA can also be used to exchange objects Web-Based Information Systems

Terms in the Glossary • Internet: group of networks connected together. The Internet refers to the global connection of networks around the world. • LAN: Local Area Network: a group of computers, usually all in the same room or building, connected for the purpose of sharing files, exchanging email, and collaboration. • Intranet: internal company network. Internal use of web capabilities. • Extranet: ability to securely connecting the intranet with defined external networks. • CGI: Common Gateway Interface: means of developing application for the web on the server side. • Middleware: a tier usually between a web application or a web server and a database or another application layer. Web-Based Information Systems

Web-Based Information Systems