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Web-Based Information Course Content Systems Introduction Perl - - PowerPoint PPT Presentation

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Web-Based Information Course Content Systems Introduction Perl & Cookies Internet and WWW SGML / XML Fall 2004 Protocols CORBA & SOAP HTML and beyond Web Services CMPUT 410: Internet and WWW

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SLIDE 1

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

1

Web-Based Information Systems

  • Dr. Osmar R. Zaïane

University of Alberta

Fall 2004

CMPUT 410: Internet and WWW

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

2

  • Perl & Cookies
  • SGML / XML
  • CORBA & SOAP
  • Web Services
  • Search Engines
  • Recommender Syst.
  • Web Mining
  • Security Issues
  • Selected Topics

Course Content

  • Introduction
  • Internet and WWW
  • Protocols
  • HTML and beyond
  • Animation & WWW
  • CGI & HTML Forms
  • Javascript
  • Databases & WWW
  • Dynamic Pages

Preliminaries

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

3

Objectives of Lecture 2

  • 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.

Internet and WWW Internet and WWW

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

4

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
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SLIDE 2

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

5

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

6

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

7

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

8

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

  • f connected parts of documents.

Hyperlinks are links that connect sub-

  • documents. Hypermedia is a multimedia

hypertext document,

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SLIDE 3

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

9

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

10

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

11

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

12

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.

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SLIDE 4

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

13

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

CA net

Year Speed USA equivalent Canada committed $110 million for Ca net4, a10 Gb/s optical network connecting research institutions across Canada.

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

14

Explosive Growth

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

15

1973 First international connection (UK+Norway)

1970 1995 1990 1985 1980 1975

1969 ARPANET commissioned by DoD 1974 TCP/IP 1979 USENET 1982 ARPANET transition to TCP/IP 1986 NSF-Net created 1990 ARPANET ceases to exist 1990 Archie 1988 IRC

2000

1991 Gopher 1991 WAIS 1992 WWW in CERN 1992 MBONE 1992 Veronica 1993 Mosaic 1993 Crawlers 1995 Java 1995 VRML 1994 E-commerce 1996 Internet phone 1972 ARPANET demonstration 1981 BITNET and CSNET come into being 1983 ARPANET splits into ARPANET and MILNET 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 313,000 1990 1,486,000 1993 6,642,000 1995 36,739,000 1998 # hosts Year 213 1981 1,961 1985 1994 UCSTRI 1993 Aliweb 1994 MLDB + WebQL 1991 Netfind 1994 Yahoo 1985 FTP 1997 Wireless Internet access 1998 Internet Tax Freedom Act 1996 AltaVista 1986 NNTP 1999 Internet2 NGI 1999 RSVP 1994 Harvest 1996 WebSQL 1997 WebOQL 1998 Google 1998 Clever 1993 W3C 1971 FTP on NCP

Internet Timeline

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

16

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
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SLIDE 5

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

17

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

18

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

19

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

20

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
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SLIDE 6

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

21

Client-Server Architecture

The World-Wide Web is an assortment of interconnected

  • computers. In this context,

computers provide data to

  • ther computers.

Provides the information Requests the information

Server Client

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

22

Client-Server Architecture

Request Response URL HTML page Server Client HTTP

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

23

Client-Server Architecture

Request + Data Response HTTP DB HTTP server Browser Application CGI + Servlets (Perl and Java) Javascript and Java

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

24

Application / Application Communication – scenario 1

Request + Data Response HTTP DB HTTP server No browser involved

Application Identifying fields and variables Application Parses the HTML page to extract the needed information

Wrapper needed Wrapper needed

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SLIDE 7

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

25

Application / Application Communication – scenario 2:

XML request + Data Response HTTP DB HTTP server CORBA can also be used to exchange objects

Application parses XML with known DTD or schema

SOAP over

XML doc XML doc

Web Service

Web-Based Information Systems University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

26

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 University of Alberta

 Dr. Osmar R. Zaïane, 2001-2004

27

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.