University of Alberta Dr. Osmar R. Zaïane, 2001-2004 1 Web-Based Information Systems Dr. Osmar R....

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


• 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


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 WWWInternet and WWW


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


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.


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.










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,










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...


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


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.


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 netYear Speed USA equivalent

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


Explosive Growth


1973First internationalconnection (UK+Norway)

1970 19951990198519801975

1969ARPANETcommissioned

by DoD

1974

TCP/IP 1979USENET

1982ARPANETtransition to

TCP/IP

1986NSF-Netcreated

1990ARPANETceases to exist

1990Archie

1988IRC

2000

1991Gopher

1991WAIS

1992WWWin CERN

1992MBONE

1992Veronica

1993Mosaic

1993Crawlers

1995Java

1995VRML

1994E-commerce

1996Internet phone

1972ARPANETdemonstration

1981BITNETand CSNET come into being

1983ARPANET splitsinto ARPANET and MILNET

11969

31973

111989

331991

491992

591993

811994

961995

1341996

1711997

# countriesYear

41969

621974

313,0001990

1,486,0001993

6,642,0001995

36,739,0001998

# hostsYear

2131981

1,9611985

1994UCSTRI

1993Aliweb

1994MLDB +WebQL

1991Netfind

1994 Yahoo

1985FTP

1997WirelessInternet access

1998Internet TaxFreedom Act

1996AltaVista

1986NNTP

1999Internet2NGI

1999RSVP

1994Harvest

1996WebSQL

1997WebOQL

1998Google

1998Clever

1993 W3C

1971FTP on NCP

Internet Timeline










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.


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)


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.










Client-Server Architecture

The World-Wide Web is an assortment of interconnected computers. In this context, computers provide data to other computers.

Provides the informationRequests the

information

ServerClient



Request

Response

URL

HTML page

ServerClientHTTP



Request + Data

Response

HTTP

DB

HTTP serverBrowser

Application

CGI + Servlets(Perl and Java)

Javascript and Java


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

Wrapperneeded

Wrapperneeded


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

XMLdoc

XMLdoc

Web Service










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.

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