Information systems slide technical aspects of e commerce part 1

Web Server CGI Script Operating System Card HD Controller Hard Drive Motherboard... Client makes request to Web Server PC Internet Web Server FW PC PC PC Mail Server SQL Server File Serv

Technical Aspects of

E-Commerce Part 1 of 2

Mort Anvari

- Overview of Sample Network

- Definitions

- Transaction Walk Through

- The E-Commerce Application

- Web Servers

- Operating Systems

- Hardware

Sample Network

PC Internet

Web Server

FW

PC PC

PC

PC

Mail Server

SQL Server

File Server

Web Server CGI Script

Operating System

Card

HD Controller

Hard Drive

Motherboard

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.

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

Example 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

Example Transaction

1 Client makes request to Web Server

PC Internet

Web Server

FW

PC PC

PC Mail

Server

SQL Server

File Server

Example Transaction

2 Web server fetches HTML page

containing a form from the hard drive

Web Server CGI Script

Operating System

I/O Layer

HTML Pages

Motherboard

Example Transaction

3 Server sends page to client

PC Internet

Web Server

FW

PC PC

PC Mail

Server

SQL Server

File Server

Example Transaction

4 User fills in form and clicks on submit button.

PC Internet

Web Server

FW

PC PC

PC

PC

Mail Server

SQL Server

File Server

Example 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

Web Server

FW

PC PC

PC Mail

Server

SQL Server

File Server

Example Transaction

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

Web Server CGI Script

Operating System

I/O Layer

HTML Pages

Video Card

Example Transaction

7 CGI script validates the “form” data.

Web Server CGI Script

Operating System

Video Card

PC PC

PC

PC

Mail Server

SQL Server

File Server

PC PC

PC Mail

Server

SQL Server

File Server

Example 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

HTML Pages

Video Card

Example Transaction

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

Web Server CGI Script

Operating System

Video Card

PC PC

PC

PC

Mail Server

SQL Server

File Server

The 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

The E-Commerce App

Web Server CGI Script

Operating System

I/O Layer

HTML Pages

Card

HD Controller

Hard Drive

Motherboard

The E-Commerce App

- Web Page Languages

- CGI Scripts & Their Languages

- What do the scripts do?

- Prepackaged or Custom?

Web Page Languages

- HTML

- JavaScript

- Java

- ActiveX

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

Java Script

- Language designed to add minor

functionality to HTML pages

- Simple Intelligence

- Sample Apps: counters, audio

effects, calculators, scrolling text,

menus, graphic effects etc

- Sample Apps: word processors,

control systems, network services

- A mechanism for transmitting full

programs over the internet and

running them

- Arguably most powerful technology

- Major security headache

- Platform Dependant

- Faster than Java

Best Use

HTML

- The basis of all web pages

- Pages should be accessible to

HTML only browsers

JavaScript

- Add on to HTML for pizzazz

CGI 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

ASPs 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

CGI Script/ASP Languages

- Visual Basic/VB Script

- Shell Scripts

- Java

- Perl

- C/C++

Visual 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

Shell 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

- 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

- An extremely versatile language

designed by Larry Wall

- Scripts can be written quickly and

efficiently

- A very practical language

- Platform Independent

- The Lingua Franca of professional

application development

- Easy to find programmers

- Takes longer to write in but yields a

better product

- Platform Independent

Types 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

Pre-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

- Sends HTML pages to web client

- Runs the CGI scripts

- Passes user data to the CGI scripts

Web Servers

Web Server CGI Script

Operating System

Card

HD Controller

Hard Drive

Motherboard

Web Servers

- Microsoft IIS

- Netscape Enterprise

- Apache

Netscape Enterprise Server

- Best overall web server

- Best feature set

- Decentralized content creation

- Good security

- Multi-platform

- Relatively costly

- Not user friendly

- Features may need to be added

Reliability Chart

Scalability Chart

Manageability Chart

Security Chart

User Friendliness Chart

Price Chart

Best 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

Best Uses for Servers

Apache

- Low, medium or high traffic sites

- E-Commerce capable

- Best overall server

- Not for technical newcomers

Operating 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

Operating Systems

Web Server CGI Script

Operating System

Card

HD Controller

Hard Drive

Motherboard

- Collection of similar OSes

- HP/UX, Solaris, AIX

- Best is all categories except

- Free version of Unix

- Huge momentum in marketplace

User Friendliness Chart

Best Uses of Each OS

- Low to medium traffic

- Be very careful with E-Commerce

- Best for low-tech firms

Best Uses of Each OS

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

Web Server CGI Script

Operating System

I/O Layer

HTML Pages

Card

HD Controller

Hard Drive

Motherboard

- 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

Hard Drives

- Highly Redundant Drive Enclosure

External to server Can lose multiple drives Very fast

Very expensive

Backup 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

Network Interfaces

- LAN (Local Area Network)

Small in geographic size

Fast and cheap

Owned

- WAN (Wide Area Network)

Connects distant LANs

Slow and expensive

Rented

Random Access Memory

- Regular

Garden variety memory

- Parity

Checks for memory errors

Stops machine on error

- ECC (Error Checking and Correcting)

Checks for memory errors

Corrects errors

Next Time

PC Internet

Web Server

FW

PC PC

PC

PC

Mail Server

SQL Server

File Server