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thickbugΛογισμικό & κατασκευή λογ/κού

28 Οκτ 2013 (πριν από 4 χρόνια και 2 μήνες)

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© Minder Chen, 1996
-
2013

Web Architecture
-

1

The Architecture of Internet and WWW

Web

Browser

Client

Web

Server

End User

HTTP

TCP/IP

HTML

documents

Internet

or

Intranet

Benefits of the Web as a delivery mechanism:


Thin clients


Platform independence


Easy for deployment/upgrade


Based on standards




© Minder Chen, 1996
-
2013

Web Architecture
-

2

Internet: The Virtual Network & Internal Structure

Computer

Router

A Regional Network

Internet

NAP

ISP

LAN

NAP: National Access Point ISP: Internet Service Provider

TELCO

© Minder Chen, 1996
-
2013

Web Architecture
-

3

Hosts on the Internet


IP Datagram


Datagram Header


Source: 15.127.9.12 (IP Address)


Destination: 254.231.15.129


American Registry for Internet Numbers https://www.arin.net/

Router

Total about 4.3 billion IP addresses.

© Minder Chen, 1996
-
2013

Web Architecture
-

4

Domain Name


DNS (Domain Name Server): Mapping the four octets (32
-
bit numeric)
IP address (such as 217.156.3.14) to a domain name such as
student.csuci.edu


http://www.godaddy.com

for domain name registration


edu

uiuc

csuci

cs

vax

The name of a host computer
with an IP address

student

First Level

Second
Level

CSUCI.EDU

Top
country
domain
name

.us

.tv (30M)

.md

© Minder Chen, 1996
-
2013

Web Architecture
-

5

Key Elements of Web


Hypertext
: Non
-
linear links to anchors of the
same document, or to different documents on
the same or different web site.


Using HTML (HyperText Markup Language) links and
anchors


Relying on URL (Uniform Resource Locators)
addressing scheme


Multimedia: graphics, video, sound, etc.


Web browser can access networked hypermedia.


Hypermedia access of the web browser is facilitated
by helper applications, plug
-
ins, or document
viewers.


Network: Global reach and "Universal" access


Based on HTTP which is built on top of the TCP/IP
protocol.

© Minder Chen, 1996
-
2013

Web Architecture
-

6

Client
-
Server Model of http

Web Server

Web Client


Requesting a
document via a
URL address


Connection open


Returning MIME
-
compliance document


Connection close

helper app

helper app

helper app

helper app

helper app

Web contents


HTML documents


Images


Animation


Video clips


Sound bites


Java applets


Java Scripts


CGI scripts


JSP


Database access


ASP/ASPX/PHP


JSP

Web Site

Internet or

Intranet

1

2

Static

Dynamic

MIME: Multipurpose Internet Mail Extension

© Minder Chen, 1996
-
2013

Web Architecture
-

7

HTTP


HTTP: HyperText Transfer Protocol


Characteristics:


Runs on top of TCP/IP (Transmission Control
Protocol/Internet Protocol)


Has a comprehensive addressing scheme, i.e. URL


An extensible and open representation for data type,
using MIME header


Has a
stateless

protocol. There is no
memory
between client connections.


Cookies are used to
track users.


Is efficient


Is portable


Possible extensions, Secure HTTP (SHPPT), SSL.
(
https
://URL)

© Minder Chen, 1996
-
2013

Web Architecture
-

8

The Extended Framework of WWW

Web

Browser

Client



HTML
Authoring

Tools/Editors

End User

Web Master

Web Designer

& Publisher

External Applications

Non
-
HTTP objects


ColdFusion,


CGI (Perl)


ASP & ASP.NET


JAVA Servlet


Java Server
Pages


Java Applet


JavaScript

Internet


Global Reach

Broad Range

Web Programmer

Web

Server



<html>

<head>

<title> HTML Sampler Web Page </title>

</head>

<body>

<h1>HTML Sampler</h1>

<img src="eyes.gif"><br>

<b> List: </b>

<ul>

<li> Item 1

<li> <font size=+2>Item 2</font>

<li> <i>Item 3</i>

</ul>

<table border=1>

<tr> <th> Name</th> <th>Speciality </th> </tr>

<tr> <td> Minder Chen</td> <td>MIS </td> </tr>

<tr> <td> Justin Chen</td> <td>Aerospace </td> </tr>

</table>

<p>

A sample of a form:

<form method="post"

action="http://hoohoo.ncsa.uiuc.edu/cgi
-
bin/post
-
query" >

Name: <input type="text" size=20> <br>

<input type="checkbox" name="html" value="YES"> Know HTML <br>

<b><input type="submit" value="Submit your data"></b>

</form>

<hr> Developed by

<a href="http://www.erols.com/aitc/"> Advanced IT Consulting</a>

</body></html>

© Minder Chen, 1996
-
2013

Web Architecture
-

10

HTTP (Web) Cookie


First party and third party Cookies at http://on.wsj.com/LamyJX


This is how most web sites used to track
you and maintain online sessions.

© Minder Chen, 1996
-
2013

Web Architecture
-

11

Clickstream


Hit


any Web server request that generates a log file entry. A
page has many elements (html, gifs), each generating a hit.


Page


Web server file that is sent to client user agent, usually a
browser.


Session


all actions (i.e. requests, resets) made in single visit,
from entry until logout or time out (e.g., 20 minutes of no
activity).


Visitor


a user or bot/spider/crawler that makes requests at a
site. Can be new, returning, registered, anonymous


Buyer


visitor that purchases something


Customer


a visitor that registers (sometimes defined as buyer)


Conversion


rate at which visitors transition to desired state


(buyers, customers, registered, started checkout)


Host


remote machine, identified by IP address, used for visit.


Referrers


page that provides a link to another page. Can be
internal or external

© Minder Chen, 1996
-
2013

Web Architecture
-

12

Web Log Analysis


Number of visits and number of unique visitors


Visits duration and last visits


Authenticated users, and last authenticated visits


Days of week and rush hours


Domains/countries of host's visitors.


Hosts list


Number total pageviews


Most viewed, entry and exit pages


Files type


OS

used


Browsers

used


Robots


HTTP referrer


Search engines
, key phrases and keywords used to find the analyzed web
site


HTTP errors


Some of the log analyzers also report on who's on the site, conversion
tracking, visit time and page navigation.