1. Electronic Commerce Eighth Edition
Chapter 8 Web Server Hardware and Software 1 1

2. Learning Objectives In this chapter, you will learn about:
Web server basics
Software for Web servers
management and spam control issues
Internet and Web site utility programs
Web server hardware
Electronic Commerce, Eighth Edition 2 2

3. Web Server Basics Chapter topics
Basic technologies to build online business Web sites
Server software and hardware
Utility function software
Web server
Main job: respond to Web client requests
Main elements: hardware, operating system software, Web server software
Web site goals followed by site development
Perform site estimates
Determine hardware and software combination
Electronic Commerce, Eighth Edition

4. Types of Web Sites Web site planning is first step
Determine site goals
Estimate visitors, types of files
Assess existing information technology staff
Five Web site categories
Development sites: evaluate Web designs
Intranets: house internal information
Extranets: allow outside party access
Transaction-processing sites: commerce site
Content-delivery sites: deliver news, histories, summaries, digital content
Electronic Commerce, Eighth Edition

5. Web Clients and Web Servers
Client/server architectures
Client requests services from server
Client computer
Uses Web browser software (Web client software)
Server computer
More memory and larger, faster disk drives
Platform neutral Web software
Various computers communicate easily, effectively
Critical ingredient for rapid spread, widespread Web acceptance
Electronic Commerce, Eighth Edition

6. Electronic Commerce, Eighth Edition

7. Dynamic Content Server performance affected by: Dynamic page
Web page mix and type delivered to client
Dynamic page
Client Web page content shaped by program
Static page
Unchanging page retrieved from disk
Sometimes stored in Web server’s active memory
Static versus dynamic page delivery
Static page requires less computing power
Servers delivering mostly static pages perform better
Electronic Commerce, Eighth Edition

8. Dynamic Content (cont’d.)
Nonstatic information constructed in response to Web client’s request
Example: order inquiry with unique customer number
Web sites using collection of HTML pages
Changed by editing HTML (cumbersome)
Specific query-customized pages not allowed
Create customized pages on the fly using:
Server-side scripting
Dynamic page-generation technology
Electronic Commerce, Eighth Edition

9. Dynamic Content (cont’d.)
Server-side scripting
Used by first Web sites providing dynamic pages
Also called:
Server-side includes
Server-side technologies
Web server programs create Web pages before sending pages back to client
Server-side technologies are slow
Large online business Web sites alternative
Dynamic page-generation technologies
Electronic Commerce, Eighth Edition

10. Dynamic Content (cont’d.)
Dynamic page-generation technologies
Examples
Microsoft Active Server Pages (ASP)
Sun Microsystems JavaServer Pages (JSP)
Open-source Apache Software Foundation Hypertext Preprocessor (PHP)
Adobe Cold Fusion
Dynamic Web page creation
Server-side scripts mix with HTML tagged text
Java servlets
Server-side programs created using Java programming language (Sun)
Electronic Commerce, Eighth Edition

11. Dynamic Content (cont’d.)
Dynamic page-generation technologies (cont’d.)
Popular tools to generate dynamic Web pages and make them interactive
AJAX (asynchronous JavaScript and XML): creates interactive Web sites looking like applications
Ruby on Rails: creates dynamic Web pages with interface looking like application
Python scripting language
Electronic Commerce, Eighth Edition

12. Dynamic Content (cont’d.)
The future of dynamic Web page generation
Criticisms of previous approaches
Do not solve problem of dynamic page generation
Shift dynamic page creation from HTML coders to ASP (JSP, PHP) programmers
Apache Cocoon project initiative
Query XML formatted data and generate output in multiple formats
HTML output: useful for dynamic Web page creation
May apply style sheet to data: tailored response
Portable Document Format (PDF) file, Wireless Markup Language (WML) file
Electronic Commerce, Eighth Edition

13. Dynamic Content (cont’d.)
The future of dynamic Web page generation (cont’d.)
Latest Cocoon version
Divides work into four areas of concern
Limits area interactions to five specific contracts
Breaks direct connection between logic and style
Future dynamic Web page design easier
Other initiatives
Microsoft: Microsoft.NET Framework
Oracle: including explicit PHP support (other scripting languages) in its database products
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14. Electronic Commerce, Eighth Edition

15. Various Meanings of “Server”
Any computer providing files (programs) to other computers
Connected through network
Server software
Server computer software
Makes files (programs) available to other computers
Sometimes included with operating system
Servers connect through router to the Internet
Run Web server software
Electronic Commerce, Eighth Edition

16. Various Meanings of “Server” (cont’d.)
Web servers
Computers connected to the Internet
Run Web server software
Makes server’s files available to other computers
server: handles incoming, outgoing
Database server
Runs database management software
“Server” describes several types of computer hardware, software
Note context
Electronic Commerce, Eighth Edition

17. Web Client/Server Communication
Web browser requests files from Web server
Transportation medium: the Internet
Request formatted by browser using HTTP
Request sent to server computer
Server receives request
Retrieves file containing requested Web page
Formats using HTTP
Sends back to client over the Internet
Client Web browser
Browser displays information if it is an HTML page
Graphics can be slow to appear
Electronic Commerce, Eighth Edition

18. Two-Tier Client/Server Architecture
Messages created and read
Only by client and server computers
Request message: client requesting file from server
Request line: contains command, target resource name, protocol name, version number
Optional
Request headers: file type information that client will accept
Entity body: passes bulk information to server
Electronic Commerce, Eighth Edition

19. Two-Tier Client/Server Architecture (cont’d.)
Server receives request message
Executes command included in message
Retrieves file from disk
Creates response message: sent back to client
Identical structure as request message (slightly different function)
Response header line: server HTTP version, response status, status information explanation
Response header field: information describing server’s attributes
Entity body: returns HTML page requested by client (optional)
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21. Three-Tier and N-Tier Client/Server Architectures
Three-tier architecture
Extends two-tier architecture
Allows additional processing before server responds to client’s request
n-tier architectures
Higher-order architectures; more than three tiers
Third tier supplies information to Web server
Databases and related software application
Electronic Commerce, Eighth Edition

22. Three-Tier and N-Tier Client/Server Architectures (cont’d.)
Four, five (or more) tiers include:
Software applications (like three-tier systems)
Databases, database management programs
Work with software applications, generate information turned into Web pages, send to requesting client
Example: catalog-style Web site
Search, update, display functions
Track customer purchases stored in shopping carts, look up sales tax rates, keep track of customer preferences, query inventory databases, keep company catalog current
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23. Electronic Commerce, Eighth Edition

24. Software for Web Servers
Web server software
May run on:
One or several computer operating systems
Types of Web server software/programs
Operating system software
Web server software itself
Other programs
Internet utilities
software
Electronic Commerce, Eighth Edition

25. Operating Systems for Web Servers
Operating system tasks
Running programs, allocating computer resources, providing input and output services
More responsibilities (large systems)
Tracking multiple users, ensuring no interference
Microsoft Windows Server products
Considered simple to learn and use
Raise security concerns
Linux-, UNIX-based products
Popular
Considered secure as Web servers
Electronic Commerce, Eighth Edition

26. Operating Systems for Web Servers (cont’d.)
Linux (open-source operating system)
Fast, efficient, installs easily
Open-source software
Developed by community of programmers
Software available for download (free)
Others use it, improve it, submit improved versions
More information
Open Source Initiative Web site
Electronic Commerce, Eighth Edition

27. Operating Systems for Web Servers (cont’d.)
Companies selling Web server computers
Include Linux in default configurations
Companies may buy Linux through commercial distributors
Include useful additional software (installation utilities)
Provide support contracts
Examples: Mandriva, Red Hat, SCO Group, SuSE
Sun Microsystems
Sells Web server hardware
Solaris: UNIX-based operating system
Electronic Commerce, Eighth Edition

28. Web Server Software Commonly used Web server programs
Apache HTTP Server, Microsoft Internet Information Server (IIS), Sun Java System Web Server (JSWS)
Netcraft networking consulting company Web survey
Measures Web server software’s relative popularity
Stabilizing in recent years
See Figure 8.5
Web server performance differences
Workload, operating system, Web pages served
Critical: choose right server for each business need
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30. Web Server Software (cont’d.)
Apache HTTP Server
1994: Rob McCool developed Apache
Original core system with lots of patches
Known as “a patchy” server
Ongoing group software development effort
Dominated Web since 1996
Free, performs efficiently
In IBM WebSphere application server package
Zeus based on Apache open-source code
Most widely installed Web server software package
Runs on many operating systems, hardware
Electronic Commerce, Eighth Edition

31. Web Server Software (cont’d.)
Microsoft Internet Information Server
Bundled with Microsoft Windows Server operating systems
Runs on Windows server operating system (by design)
Used on many corporate intranets
Adopted Microsoft products as standard products
ASP, ActiveX Data Objects, SQL database queries
Microsoft FrontPage Web site development tool, reporting tools
HTML pages, ActiveX components, scripts can be combined to produce dynamic Web pages
Electronic Commerce, Eighth Edition

32. Web Server Software (cont’d.)
Sun Java System Web Server (Sun ONE, iPlanet, Netscape)
Original NCSA Web server program descendent
Former names: Sun ONE, Netscape Enterprise Server, iPlanet Enterprise Server
AOL-Sun Microsystems partnership called iPlanet
Agreement expired March 2002
iPlanet became part of Sun
Not free: reasonable licensing fee
Runs on many operating systems
Electronic Commerce, Eighth Edition

33. Web Server Software (cont’d.)
Sun Java System Web Server (Sun ONE, iPlanet, Netscape) (cont’d.)
Web server use
One percent of all Web servers
Busiest and best-known Internet sites: BMW, Dilbert, E*TRADE, Excite, Lycos, Schwab
More than 30 percent of all public Web sites
More than half of top 100 enterprise Web sites
Supports dynamic application development
Provides connectivity to database products
Electronic Commerce, Eighth Edition

34. Finding Web Server Software Information
The Netcraft Web site home page
“What’s that site running?” link
Leads to page with search function
Find out operating system, Web server software specific site now running
Find out what site ran in the past
Electronic Commerce, Eighth Edition

35. Electronic Mail (E-Mail)
Electronic commerce important technologies
Web: interactions between Web servers and clients
Gather information, execute transactions, perform other electronic commerce-related tasks
1970s origin: ARPANET
Most popular form of business communication
Far surpassing: telephone, conventional mail, fax (in volume)
Electronic Commerce, Eighth Edition

36. E-Mail Benefits Reason many people attracted to the Internet
Conveys messages in seconds
Simple ASCII text, character formatting
Useful feature
Attachments: most important message part
uses
Confirm receipt of customer orders, confirm shipment of items ordered, send information about a purchase to buyer, announce specials and sales, keep in touch with customers
Electronic Commerce, Eighth Edition

37. E-Mail Drawbacks Time spent answering e-mail
Managers: five minutes per
Average person spends two hours a day
Creating resentment
Computer virus (through attachments)
Program attaches itself to another program
Causes damage when host program activated
Cost for convenience
Virus protection software, dealing with security threats
Spam (unsolicited commercial )
Most frustrating and expensive problem
Electronic Commerce, Eighth Edition

38. Spam Magnitude of spam problem 24-hour period in 2008
220 billion spam messages sent
Researchers believe:
More than 98 percent of all messages will be spam before effective technical solutions implemented
Spam leveling off (approaching 100 percent)
Absolute spam numbers could continue to grow rapidly
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39. Electronic Commerce, Eighth Edition

40. Spam (cont’d.)
AOL active has taken active role limiting spam through legal channels
2005: temporary decline
Now: resumed increase
Antispam efforts
Limit spam annoyance and cost
server computer software
Limit amount of spam getting through to employees
Individual users
Install client-based spam-filtering programs, set filters
More effective, less costly to eliminate spam before downloaded
Electronic Commerce, Eighth Edition

41. Solutions to the Spam Problem
Some solutions require:
Passing of new laws
Technical changes in Internet mail-handling systems
Other approaches
Implemented with existing laws and current technologies
Requires cooperation from large numbers of organizations and businesses
Individual users
Few tactics available to reduce spam
Electronic Commerce, Eighth Edition

42. Solutions to the Spam Problem (cont’d.)
Individual user antispam tactics
Focus
Limit spammer’s access to (use of) address
Use complex address
Control address exposure; software robots
Discussion boards, chat rooms, other online sources
Use multiple addresses
Switch to another if spammers uses one
Electronic Commerce, Eighth Edition

43. Solutions to the Spam Problem (cont’d.)
Basic content filtering
Requires software
Identifies content elements in incoming message
Content-filtering techniques differ in terms of:
Content elements examined
Looking for message spam indications
How strictly message classification rules applied
Basic content filters examine headers
Filtering task software location
Client-level filtering: individual users’ computers
Server-level filtering: mail server computers
Electronic Commerce, Eighth Edition

44. Solutions to the Spam Problem (cont’d.)
Basic content filtering (cont’d.)
Black list spam filter
Looks for known spammers From addresses in incoming messages
White list spam filter
Looks for good sender From addresses in incoming messages
High false positives rate: messages rejected (should not have been)
Used in client-level or server-level filters
Overcome individual drawbacks: use approaches together with other content-filtering approaches
Electronic Commerce, Eighth Edition

45. Solutions to the Spam Problem (cont’d.)
Challenge-response content filtering
Compares all incoming messages to a white list
If sender not on white list, automated response sent (challenge)
Challenge asks sender to reply to (response)
Reply must contain response to a challenge presented in the
Designed so human can respond easily
Drawbacks
Victim bombarded; perpetrator includes victim’s
Doubles amount of useless messages sent
Electronic Commerce, Eighth Edition

46. Solutions to the Spam Problem (cont’d.)
Advanced content filtering
Uses indicators
Words, word pairs, certain HTML codes, information about where word occurs
Looks for spam indicators (entire message)
Indicator identified; message’s spam “score” raised
Problems
Spammers stop including defined indicators
Challenge creating effective content filters
Filtering “sex” may delete valid with “Essex”
Electronic Commerce, Eighth Edition

47. Solutions to the Spam Problem (cont’d.)
Advanced content filtering (cont’d.)
Approach based on branch of applied mathematics
Bayesian statistics
Bayesian revision statistical technique
Additional knowledge used to revise earlier probability estimates
Naïve Bayesian filter
Software begins by not classifying messages
User reviews messages
Message type indicated to software: spam (not spam)
Software gradually learns message element
Electronic Commerce, Eighth Edition

48. Solutions to the Spam Problem (cont’d.)
Advanced content filtering (cont’d.)
Naïve Bayesian filter success rates
Few dozen messages classified: 80 percent effective
Eventually: effective rate rises above 95 percent
2002: POPFile released
First functional Bayesian filter product for individuals
Open-source software development project
Installs on individual client computers
Works with many different clients: Post Office Protocol (POP) connection required
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50. Solutions to the Spam Problem (cont’d.)
Advanced content filtering (cont’d.)
POPFile success
Initially caught 30 percent of spam messages
After two weeks: caught more than 90 percent
Eventually: caught more than 99 percent
False positives: small rate
POPFile magnet feature
Implement white and black list filtering
Naïve Bayesian filters’ effectiveness
Very effective client-level filters
Major drawback: users must update filters regularly
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52. Solutions to the Spam Problem (cont’d.)
Legal solutions
January 2004: U.S. CAN-SPAM law went into effect
Spammers slowed down activities immediately
Seeing no threat of broad federal prosecution:
Spam rates increased
Spam estimate: over 80 percent of all messages
CAN-SPAM
Regulates all messages
Regulates messages advertising or promoting commercial product or service
Includes messages promoting Web site content
Electronic Commerce, Eighth Edition

53. Solutions to the Spam Problem (cont’d.)
Legal solutions (cont’d.)
CAN-SPAM (cont’d.)
Prohibits misleading message address header information, facilitating agreed-upon transaction or updating customer in existing business relationship
Successful prosecution: fines ($11,000) and imprisonment
Electronic Commerce, Eighth Edition

54. Solutions to the Spam Problem (cont’d.)
Legal solutions (cont’d.)
More information
U.S. Federal Trade Commission CAN-SPAM Law information pages
Few spammers prosecuted under the law
December 2003 verdict: three spammers pay more than $1 billion
2005 Jeremy Jaynes conviction: nine years in prison (appeal rejected)
FTC refused to create do-not-spam list
Electronic Commerce, Eighth Edition

55. Solutions to the Spam Problem (cont’d.)
Legal solutions (cont’d.)
CAN-SPAM (similar laws) ineffectiveness
Spammers have been violating laws for years
Mail servers located in other countries; jurisdiction unclear
Fines or collection of damages difficult to obtain
Spammers evade cease-and-desist orders; move operations from one server to another (in minutes)
Spammers hijack servers to forward mail
Hope is that CAN-SPAM and similar laws enforce constraints on legitimate marketers
Electronic Commerce, Eighth Edition

56. Solutions to the Spam Problem (cont’d.)
Legal solutions (cont’d.)
Legal solution; critics’ arguments
Failure until spammer prosecution becomes cost effective for governments
Cost effective when:
Prosecutors able to identify spammers easily
Greater likelihood of winning cases
Best way to make spammers easier to find
Make technical changes in the transport mechanism
Electronic Commerce, Eighth Edition

57. Solutions to the Spam Problem (cont’d.)
Technical solutions
Internet design not intended for today's needs
incidental afterthought
No mechanisms ensuring sender identity
Internet’s polite set of rules
Send and wait for acknowledgement (fast)
Slowing down acknowledgment messages
Originating computer will slow (must continue to scan for acknowledgment)
Will not send more messages (to that address) until acknowledgment received
Electronic Commerce, Eighth Edition

58. Solutions to the Spam Problem (cont’d.)
Technical solutions (cont’d.)
Slowing down acknowledgment messages (cont’d.)
Requires defending company to develop way to identify computers sending spam
IBM software: access to large database tracking such computers
Other vendors: software identifying multiple messages from single source in rapid succession
Once identified: software delays sending message acknowledgment
Electronic Commerce, Eighth Edition

59. Solutions to the Spam Problem (cont’d.)
Technical solutions (cont’d.)
Teergrubing: launching a return attack
Sending messages back to computer originating suspected spam
Teergrubing objective
Ensure computer sending spam is trapped
Drag down ability to send spam
Concern: counterattack might violate laws
Ultimate spam problem
New protocols providing absolute verification of message source
Electronic Commerce, Eighth Edition

60. Web Site and Internet Utility Programs
TCP/IP supports utility programs (tools)
Run on Web server or client computers
Earliest Internet utility program
Most important utility
Key element in electronic commerce strategies
Electronic Commerce, Eighth Edition

61. Finger and Ping Utilities
Finger program
Runs on UNIX operating systems
Provides information about other network users
Many organizations disable Finger command
Privacy and security
Built into some programs
Ping: Packet Internet Groper
Tests connectivity between two Internet-connected computers
Provides performance data about connection
Available as freeware and shareware
Electronic Commerce, Eighth Edition

62. Tracert and Other Route-Tracing Programs
Tracert (TRACE RouTe)
Sends data packets to every computer on path
Between one computer and another computer
Clocks packets’ round-trip times
Provides indication of time message needs to travel from one computer to another and back
Ensures remote computer online
Pinpoints data traffic congestion
Calculates and displays:
Number of hops between computers
Time to traverse entire one-way path
Electronic Commerce, Eighth Edition

63. Tracert and Other Route-Tracing Programs (cont’d.)
Tracert (cont’d.)
Sends series of packets to particular destination
Router along Internet path between originating and destination computers:
Reports IP address and time packet arrived
Graphical user interface route-tracing programs:
Provides map plot of packets’ route
Determines Internet locations with greatest delay
Example
Visualware VisualRoute route-tracing program
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65. Telnet and FTP Utilities
Telnet program: users log on to Internet-connected computer
Useful if no Web interface
Availability
Free Internet downloads: Microsoft Telnet.exe
Client computer gives commands to remote host programs
Telnet protocol: set of rules used by Telnet program
Web browser Telnet client
“telnet://” followed by remote host domain name
Telnet use decreasing
Electronic Commerce, Eighth Edition

66. Telnet and FTP Utilities (cont’d.)
File Transfer Protocol (FTP)
TCP/IP rules defining formats
Transfer files between TCP/IP-connected computers
Useful services
Displaying remote, local computers’ directories
Changing current client’s or server’s active directory
Creating and removing local and remote directories
Uses TCP and its built-in error controls:
To copy files accurately
Electronic Commerce, Eighth Edition

67. Telnet and FTP Utilities (cont’d.)
FTP remote computer access
FTP client program or browser
Protocol name (ftp://) before remote computer domain name
Full-privilege FTP
FTP connection to computer; user has account
Anonymous FTP
Guest account
Username: “anonymous”
Password: address
Electronic Commerce, Eighth Edition

68. Indexing and Searching Utility Programs
Search engines (search tools)
Search for requested documents
Specific site or entire Web
Indexing program
Provides full-text indexing
Browser search methods
Compare index terms to requester’s search term
Use complex relevance ranking rules
Advanced search engine software (Google)
Web server software contains indexing software
Electronic Commerce, Eighth Edition

69. Data Analysis Software
Web servers capture visitor information
Placed into Web log file (grows quickly)
Third-party Web log file analysis programs
Summarize log file information
Query log file
Return gross summary information or accumulating details
Popular Web log file analysis programs
Omniture, UrchinWeb Analytics, Web Side Story, WebTrends products
Electronic Commerce, Eighth Edition

70. Link-Checking Utilities
Link checker
Examines each site page
Reports broken, incorrect URLs
Identifies orphan files
Web site file not linked to a page
Script checking and HTML validation
Dead link
When clicked:
Displays error message rather than Web page
Electronic Commerce, Eighth Edition

71. Link-Checking Utilities (cont’d.)
Link-checking programs
Adobe Dreamweaver, Elsop LinkScan
Reverse link checker
Checks company’s link exchange program sites
Ensures link exchange partners fulfilling obligation
Include link back to company’s Web site
Example: LinxCop
Electronic Commerce, Eighth Edition

72. Remote Server Administration
Web site administrator controls Web site
From any Internet-connected computer
Provides convenience
Examples
Website Garage
NetMechanic
Electronic Commerce, Eighth Edition

73. Web Server Hardware Hosting electronic commerce operations
Use wide variety of computer brands, types, sizes
Some small companies run Web sites on desktop PCs
Most Web sites operated on computers
Designed for site hosting
Electronic Commerce, Eighth Edition

74. Server Computers Use more capable hardware elements
Usually more expensive than workstation PCs
Price range of Web server computer
Between $3000 and $200,000
Companies selling Web server hardware
Provide Web site configuration tools
Visitors design their own Web server
Housing Web server computers
Freestanding cases
Installed in equipment racks
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76. Server Computers (cont’d.)
Blade servers: servers-on-a-card
Small: 300 installed in single 6-foot rack
Fundamental Web server job
Process and respond to Web client requests
Sent using HTTP
Virtual server (virtual host)
Maintains more than one server on one machine
Different groups have separate domain names
All domain names refer to same physical Web server
Electronic Commerce, Eighth Edition

77. Web Server Performance Evaluation
Benchmarking: testing to compare hardware and software performance
Elements affecting overall server performance
Hardware, operating system software, server software, connection speed, user capacity, type of Web pages being delivered
Connection speed (T3 faster than T1)
Number of users server can handle
Important
Hard to measure
Electronic Commerce, Eighth Edition

78. Web Server Performance Evaluation (cont’d.)
Throughput: number of HTTP requests hardware and software combination can process
Unit of time
Response time: time that server requires to process one request
Choosing Web server hardware configurations
Run tests on various combinations, consider scalability, compare standard benchmarks
Use independent testing labs: Mindcraft
Run benchmarks regularly
Provide site visitors with best service possible
Electronic Commerce, Eighth Edition

79. Web Server Hardware Architectures
Electronic commerce Web sites use tiered architecture
Divides work of serving Web pages
May use more than one computer within each tier
Server farms: large collections of servers
Lined up row after row
Centralized architecture
Uses a few large and fast computers
Requires expensive computers
More sensitive to technical problems
Requires adequate backup plans
Electronic Commerce, Eighth Edition

80. Web Server Hardware Architectures (cont’d.)
Distributed architecture (decentralized architecture)
Uses a large number of less powerful computers
Spreads risk over large number of servers
Servers are less expensive
Requires additional hubs or switches to connect servers to each and the Internet
Requires cost of load balancing
Electronic Commerce, Eighth Edition

81. Web Server Hardware Architectures (cont’d.)
Load-balancing systems ($ $50,000)
Network hardware monitoring; server workloads
Assigns incoming Web traffic to server with most available capacity
Simple load-balancing system
Traffic enters through site’s router
Encounters load-balancing switch
Directs traffic to best Web server
More complex load-balancing systems
Incoming Web traffic enters from two or more routers
Directed to groups of dedicated Web server
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84. Summary Client/server Web architecture
HTTP-based tiered architectures
Operating systems commonly used on Web servers
Web server utility programs
benefits and drawbacks
Spam description and solutions
Web server hardware
Important consideration in online business site design
Web server performance
Factors and solutions
Electronic Commerce, Eighth Edition