Technical Aspects ofTechnical Aspects ofE-Commerce Part 1 of 2E-Commerce Part 1 of 2

Mort AnvariMort Anvari

2

IntroductionIntroduction

- Overview of Sample Network

- Definitions

- Transaction Walk Through

- The E-Commerce Application

- Web Servers

- Operating Systems

- Hardware

3

Sample NetworkSample Network

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

4

ArchitectureArchitecture

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

Physical World

NetworkCard

Software

HardwareVideoCard

HD Controller

Hard Drive

Motherboard

5

DefinitionsDefinitions

Scalability - The ability of a product to work well as it or it’s environment is changed in size or power.

Reliability - The ability of product to continue working in adverse situations or with bad data.

TCO - Total Cost of Ownership. How much a product costs over it’s life span.

6

DefinitionsDefinitions

Manageability - The ease with which a product can be maintained. Also, the degree of control allowed by the vendor.

User Friendliness - The ease with which and untrained person can use a product.

Security - The ability of a product to protect itself from malicious attack.

7

Example TransactionExample Transaction

In our example, the user wants to get their bank statement for the month as well as their bank balances. This is representative of small to medium size e-commerce sites. Larger sites use much of the same components, but more powerful or in larger quantities.

8

Example TransactionExample Transaction

1. Client makes request to Web Server

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

9

Example TransactionExample Transaction

2. Web server fetches HTML page containing a form from the hard drive

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

Physical World

NetworkCard

VideoCard

Motherboard

10

Example TransactionExample Transaction

3. Server sends page to client

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

11

Example TransactionExample Transaction

4. User fills in form and clicks on submit button.

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

12

Example TransactionExample Transaction

5. Browser sends contents of form to web server requesting that it be passed to a specific cgi script. The name of the script to be executed is embedded in the form.

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

13

Example TransactionExample Transaction

6. Web server executes CGI script and passes it form data.

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

NetworkCard

VideoCard

Motherboard

HD Controller

Hard Drive

Physical World

14

Example TransactionExample Transaction

7. CGI script validates the “form” data.

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

NetworkCard

VideoCard

Motherboard

HD Controller

Hard Drive

Physical World

15

Example TransactionExample Transaction

8. The script contacts the SQL server and requests the account history and balances using the account number given to the script by the user.

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

16

Example TransactionExample Transaction

9. The SQL server locates the data and sends it back to the CGI Script.

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

17

Example TransactionExample Transaction

10. Using the account history and balances acquired from the SQL server, the script creates a web page. A common method is to have a template file that contains the basic HTML formatting and fill in the body with dynamic data.

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

NetworkCard

VideoCard

Motherboard

HD Controller

Hard Drive

Physical World

18

Example TransactionExample Transaction

11. The CGI script passes the newly formed page to the web server.

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

NetworkCard

VideoCard

Motherboard

HD Controller

Hard Drive

Physical World

19

Example TransactionExample Transaction

12. Web server sends the final page to the client PC’s browser which displays it for the user.

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer

20

The E-Commerce AppThe E-Commerce App

What is it?- Set of software components and web data

- Made to conduct business transactions

- Designed to interact with both web users and internal company systems

- It is the web site

- All other components act as support for this piece

21

The E-Commerce AppThe E-Commerce App

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

Physical World

NetworkCard

Software

HardwareVideoCard

HD Controller

Hard Drive

Motherboard

22

The E-Commerce AppThe E-Commerce App

- Web Page Languages

- CGI Scripts & Their Languages

- What do the scripts do?

- Prepackaged or Custom?

23

Web Page LanguagesWeb Page Languages

- HTML

- JavaScript

- Java

- ActiveX

24

HTMLHTML

Hyper Text Markup Language

- The Lingua Franca of the Web

- Accessible from all browsers

- No Intelligence

- Cannot be changed on the fly

- All of your pages should look good

using HTML only. The rest is gravy.

25

Java ScriptJava Script

- Language designed to add minor

functionality to HTML pages

- Simple Intelligence

- Sample Apps: counters, audio

effects, calculators, scrolling text,

menus, graphic effects etc...

26

JavaJava

- Sophisticated language and operating

environment from Sun Microsystems

- Very intelligent

- Platform Independent

- Sample Apps: word processors,

control systems, network services

27

ActiveXActiveX

- A mechanism for transmitting full

programs over the internet and

running them

- Arguably most powerful technology

- Major security headache

- Platform Dependant

- Faster than Java

28

Best UseBest Use

HTML

- The basis of all web pages

- Pages should be accessible to

HTML only browsers

JavaScript

- Add on to HTML for pizzazz

29

Best UseBest Use

Java

- Add real sophistication to web pages

ActiveX

- Add real sophistication to web pages

- Best in Intranets

- Sites may block your ActiveX

30

CGI ScriptsCGI Scripts

- CGI = Common Gateway Interface

- CGI connects web users to programs

- Script is just a normal program

- Makes web pages

- May take other, advanced actions

- Think Security: The whole world can

run programs on your server

31

ASPs and PHP3ASPs and PHP3

- ASP = Active Server Page

- PHP3 = PHP: Hypertext Preprocessor

- A very efficient replacement for CGI

- Puts tiny programs in web pages

- The programs are run before the page

is sent to the browser

- Browsers can only see the results of the

program

32

CGI Script/ASP LanguagesCGI Script/ASP Languages

- Visual Basic/VB Script

- Shell Scripts

- Java

- Perl

- C/C++

33

Visual Basic/VB ScriptVisual Basic/VB Script

- Reasonably sophisticated languages

produced by Microsoft

- Easy to find programmers

- Not Platform Independent

- Not very efficient

- VB Script is a cut-down version of

Visual Basic

34

Shell ScriptsShell Scripts

- A way of automating complex tasks in

Unix. Like a DOS batch file but far

more sophisticated

- Powerful and easy to write

- Platform Independent amongst Unixes

35

JavaJava

- Java is also used as a server side

language. It is one of the few that can

be used on both the client and server

sides.

36

PerlPerl

- An extremely versatile language

designed by Larry Wall

- Scripts can be written quickly and

efficiently

- A very practical language

- Platform Independent

37

C/C++C/C++

- The Lingua Franca of professional

application development

- Easy to find programmers

- Takes longer to write in but yields a

better product

- Platform Independent

38

Types of ScriptsTypes of Scripts

- Submit form contents into database

- Send form contents via e-mail

- Retrieve information from database

and create web page based on it

- Verify credit card transaction

- Send form contents as fax

- Send a message to a pager

39

Pre-Packaged vs. CustomPre-Packaged vs. Custom

Pre-Packaged

- Minimal Effort

- Many can be found for free

- Difficult or impossible to customize

- Licensing agreements may limit your

commercial use

40

Pre-Packaged vs. CustomPre-Packaged vs. Custom

Custom

- Expensive

- Long implementation time

- Built to suit

Hybrid

- Best overall solution

41

Web ServerWeb Server

What is it?- A software program

- Prepares HTML pages by reading them from disk or executing a CGI Script

- Sends HTML pages to web client

- Runs the CGI scripts

- Passes user data to the CGI scripts

42

Web ServersWeb Servers

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

Physical World

NetworkCard

Software

HardwareVideoCard

HD Controller

Hard Drive

Motherboard

43

Web ServersWeb Servers

- Microsoft IIS

- Netscape Enterprise

- Apache

44

Microsoft IISMicrosoft IIS

- IIS = Internet Information Server

- Inexpensive

- Solid feature set

- Fast

- Best pre-packaged site support

- Security Problems

- Platform Dependant

45

Netscape Enterprise ServerNetscape Enterprise Server

- Best overall web server

- Best feature set

- Decentralized content creation

- Good security

- Multi-platform

- Relatively costly

46

ApacheApache

- Market dominance (55%)

- Very fast, scalable & flexible

- Great support

- Best security

- Not user friendly

- Features may need to be added

47

Reliability ChartReliability Chart

1. Apache 100

2. Netscape 95

3. IIS 90

48

Scalability ChartScalability Chart

1. Apache 100

2. Netscape 90

3. IIS 45

49

Manageability ChartManageability Chart

1. Netscape 100

2. IIS 90

3. Apache 80

50

Security ChartSecurity Chart

1. Apache 100

2. Netscape 95

3. IIS 60

51

User Friendliness ChartUser Friendliness Chart

1. IIS 80

2. Netscape 70

3. Apache 35

52

Price ChartPrice Chart

1. Apache 100

2. IIS 98

3. Netscape 40

53

Best Uses for ServersBest Uses for Servers

Microsoft IIS

- Medium traffic sites

- Good for cost conscious sites

- Not good for E-Commerce

Netscape Enterprise

- Medium or high traffic sites

- Best intranet server

- E-Commerce capable

54

Best Uses for ServersBest Uses for Servers

Apache

- Low, medium or high traffic sites

- E-Commerce capable

- Best overall server

- Not for technical newcomers

55

Operating SystemOperating System

What is it?- A software program

- Manages all other programs

- Manages hardware resources

- Handles input and output from to and from devices like printers, disks, and the network

- Communicates status info to users

56

Operating SystemsOperating Systems

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

Physical World

NetworkCard

Software

HardwareVideoCard

HD Controller

Hard Drive

Motherboard

57

Operating SystemsOperating Systems

- Windows 95/98

- Windows NT

- Unix

- Linux

58

Windows 95/98Windows 95/98

- Microsoft’s consumer level OS

- Not a proper OS

- No scalability

- Inefficient

- Dies like a lemming

- It’s rubbish

- Never use it for anything serious

59

Windows NT/2000Windows NT/2000

- Microsoft’s Professional OS

- Better than 95/98 in every respect

- Inexpensive

- Excellent application support

- Security Issues

- Immature

- Highly proprietary

60

UnixUnix

- Collection of similar OSes

- HP/UX, Solaris, AIX

- Best is all categories except

User Friendliness

- Mature, Internet = Unix

- Multi-user design

- Expensive and technical

61

LinuxLinux

- Free version of Unix

- Huge momentum in marketplace

- Great support

- Friendlier than other Unixes

- E-Commerce in a box

- Not quite as good as other Unixes

62

Reliability ChartReliability Chart

1. Unix 100

2. Linux 90

3. Windows NT 40

4. Windows 95 15

5. Windows 3.11 5

63

Scalability ChartScalability Chart

1. Unix 100

2. Linux 50

3. Windows NT 20

4. Windows 95 5

64

Manageability ChartManageability Chart

1. Unix 100

2. Linux 90

3. Windows NT 60

4. Windows 95 40

65

Security ChartSecurity Chart

1. B1 Unix 100

2. C2 Unix/Linux 65

3. Windows NT 40

4. Windows 95 5

66

User Friendliness ChartUser Friendliness Chart

1. Macintosh 100

2. Windows 95 60

3. Windows NT 55

4. Linux 45

5. Unix 20

67

Price ChartPrice Chart

1. Linux 95

2. Windows 95 65

3. Windows NT 35

4. Unix 10

68

Best Uses of Each OSBest Uses of Each OS

Windows 95- Games

- Word Processing

- Not a serious OS

Windows NT- Low to medium traffic

- Be very careful with E-Commerce

- Best for low-tech firms

69

Best Uses of Each OSBest Uses of Each OS

Unix- Low, medium and high traffic

- E-Commerce capable

- Best for mega-sites

Linux

- Low, medium and high traffic

- E-Commerce capable

- Good for all uses

70

HardwareHardware

What is it?- The physical components of a computing

system

- If it can be held in your hand it’s hardware

- If it can’t it’s software

71

HardwareHardware

Web Server

CGI Script

Operating

System

I/O Layer

HTMLPagesData

UserSpace

SystemSpace

Physical World

NetworkCard

Software

HardwareVideoCard

HD Controller

Hard Drive

Motherboard

72

HardwareHardware

- Architecture

- Hard Drives

- Backup Systems

- Network Interfaces

- RAM

73

ArchitectureArchitecture

- CISC (Complex Instruction Set Comp.)Can do complex operations

Can do many functions

i.e. 486, Pentium, PowerPC

- RISC (Reduced Instruction Set Comp.)Can do a few simple operations

Faster than CISC

i.e. SPARC, HP9000

74

Hard DrivesHard Drives

- SingleA regular hard drive

- MirroredFault-Tolerant

Expensive

- Drive ArrayFault-Tolerant

Slower but cheaper than Mirror

75

Hard DrivesHard Drives

- Highly Redundant Drive EnclosureExternal to server

Can lose multiple drives

Very fast

Very expensive

76

Backup SystemsBackup Systems

- DAT (Digital Audio Tape)Fast, efficient and reliable

Tape sizes from 2-24GB

Backwards compatible

- DLT (Digital Linear Tape)Very fast, reliability problems

Tapes can hold up to 70GB

New technology

77

Backup SystemsBackup Systems

- Tape LibraryUses multiple DLTs or DATs

Uses many tapes

Robotic arm changes tapes

78

Network InterfacesNetwork Interfaces

- LAN (Local Area Network)Small in geographic size

Fast and cheap

Owned

- WAN (Wide Area Network)Connects distant LANs

Slow and expensive

Rented

79

Random Access MemoryRandom Access Memory

- RegularGarden variety memory

- ParityChecks for memory errors

Stops machine on error

- ECC (Error Checking and Correcting)Checks for memory errors

Corrects errors

80

Next TimeNext Time

PC Internet

WebServer

FWR PC

PC

PC

PC

PC

MailServer

SQLServer

FileServer