Transcript Web Server Hardware and Software

Web Server Hardware
and Software
Presented by:
Trung NGUYEN
Emilie MARTIN
Web Server Hardware and Software
Discussion Objectives
 Web server basics
 Software for Web Servers
 E-mail management and spam control
 issues
 Internet and Web site utility programs
 Web server hardware
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Web Server Basics
Web server computer’s main job: respond
to requests from Web client computers
 Web server’s main elements: hardware
(computers and related components),
operating system software, and Web
server software
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Types of Web Sites
Development sites: simple sites used to
evaluate different Web designs with little
initial investment
 Intranets: corporate networks
 Extranets: intranets that allow authorized
outsiders to access certain parts of the
system
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Types of Web Sites
Transaction-processing sites: electronic
commerce sites available 24/7
 Content-delivery sites: deliver news,
histories, summaries, and other digital
information
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Web Clients and Web Servers
Web client computer: used by people
through their Internet connections to be
part of the Web
 Web server computer: computer used to
process Web client computers’ requests;
have more memory and larger, faster disk
drives then client computers

Web Clients and Web Servers (cont.)
Web browser software (Microsoft Internet
Explorer, Netscape Navigator): software
that makes computers work as Web client,
also called Web client software
 Web software: platform neutral, let
computers communicate with each other
easily and effectively
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Figure 1
Dynamic Content
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Dynamic page: a Web page whose content is
shaped by a program in response to user
requests
Static page: an unchanging page retrieved from
disk
Dynamic content: nonstatic information
constructed in response to a Web client’s request
Two basic approaches to create
customized pages
Server-Side Scripting/Technologies : slow,
programs create the Web pages before
sending them to the requesting Web
clients as parts of response messages
 Dynamic Page-Generation Technologies:
server-side scripts are mixed with HTMLtagged text to create the dynamic Web
page.
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Two basic approaches to create
customized pages (cont.)
Dynamic Page-Generation Technologies example:
 Active Server Pages by Microsoft
 JavaServer Pages by Sun Microsystems
 Hypertext Preprocessor by open-source Apache
Software Foundation
Various Meaning of “Server”
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“Server”: confusedly used in many different ways
Server: any computer used to make
files/programs available to other computers
connected to it through a network (a LAN or a
WAN)
Server software: software that used by server
computer to make files/programs available to
other computers
Various Meaning of “Server”
Web server: computers contain document
made publicly available through Internet
connections
 Web server software: software used by
Web server
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Web Client/Server
Communication
Two-Tier Client/Server Architecture
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Basic Web client/server model, has only one
client and one server
Messages are created and read only by the client
and server computers
Figure 2
Three-Tier and N-Tier Client/Server
Architectures
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Allow additional processing to occur before the
Web server responds to the Web client’s request
Includes databases and related software
applications that supply information to the Web
server
Can track customer purchases stored in shopping
carts, look up sales tax rates, keep track of
customer preferences, query inventory databases
Figure 3
Software for Web Servers
Operating systems for Web servers:
Run programs and allocate computer
resources such as memory and disk space
to programs
 Provides input and output services to
devices connected to the computer,
including keyboard, monitor, and printers
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Operating systems
Microsoft server products:
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Windows NT Server, Microsoft Windows 2000
Server or Server 2003
Believed simpler to learn and use than UNIXbased systems
Have security weaknesses caused by the tight
integration between application software and the
operating system
Operating systems (cont.)
UNIX-based Operating System:
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Solaris or FreeBSD:
More popular, more secure operating system to
run a Web site
Operating systems (cont.)
Linux:
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Open-source operating system that is easy to
install, fast, and efficient
Open Source Initiative Web site:
www.opensource.org
Commercial Linux distributors: SuSE, Caldera,
mandrake, Red Hat
Web Server Software
Most commonly used Web server
programs (conducted by Netcraft
(England)):
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Apache HTTP Server
Microsoft Internet Infor Server (IIS)
Sun Java System (JSWS) (Sun ONE, iPlanet,
Netscape)
Web Server Software (cont.)
Apache HTTP Server:
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Developed by Rob McCool in 1994
Currently available at no cost as open-source
software
Dominated the Web since 1996
Account for 65-70% of Web server market share
Web Server Software (cont.)
Microsoft Internet Information
Server (IIS)
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Used by many corporate intranets
Account for 20-25% of Web server market share,
has been decreasing as a victim of several wellpublicized security breaches
Web Server Software (cont.)
Sun Java System Web Server (JSWS):
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Often called by Sun ONE, iPlanet Enterprise
Server, Netscape Enterprise Server
Not free, but licensing fee is reasonable
Web Server Software (cont.)
Market share for Intranet Web servers are
quite different than for public Web servers
(PC Magazine Survey)
 Microsoft IIS and Sun servers account for
75% of installed intranet server programs
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Web Server Software (cont.)
Large company Web sites and high traffic
Web sites prefer Sun servers
 Performance of Web servers differ based
on workload, operation system, type and
size of Web page servers
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Web Server Software (cont.)
Finding Web Server Software Information
Netcraft Web site: WWW.netcraft.com
Electronic Mail
.K. E-mail
Since 1972
E-mail Benefits
First Internet Application
 Attachment available
 E-mail used as a receipt of customer
orders
 Information update about purchases and
shipment
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E-mail Drawback
Time consuming
 Computer Virus
 Unsolicited commercial e-mails
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Waste of time and disk space
Consuming large amount of Internet capacity
Offensive
Tremendous growth
Solutions to the Spam Problem
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Individual User Anti-Spam
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Reduce the likelihood for automatic spam
Control exposure of an e-mail address
Use multiple e-mail addresses
Basic content filtering
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Examining e-mail headers: client-level or
server-level filtering
Black lists
White lists
Solutions to the Spam Problem
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Challenge-response content filtering
Advanced Content Filtering
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Bayesian revision
POPFile
Solutions to the Spam Problem
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Legal solutions: CAN-SPAM
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Misleading address header information
Deceptive subject headers
Clear & conspicuous notice of message nature
Physical postal address
Mandatory provision of an opt-out mechanism
Effectiveness of opt-out mechanism
Transfer of e-mail address
Technical solutions
Web Site and Internet
Utility Programs
Web Site and Internet Utility
Programs
Finger and Ping Utilities
 Tracert and other Route-Tracing Programs
 Telnet and FTP Utilities
 Indexing and Searching Utility Programs
 Data Analysis Software
 Link-Checking Utilities
 Remote Server Administration
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Server Hardware
Web Server Hardware
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Server Computers
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More memory
Larger and faster hard disk drives
Faster processors
More expensive
Blade servers
Web Server Hardware
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Web Server Performance Evaluation
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Hardware
Operating system software
Server software
Connection speed
User capacity
Type of Web pages being delivered
Speed of connection: T3 is faster than T1
Throughput
 Response time
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Web Server Hardware
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Web Server Architecture
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Centralized architecture
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Expensive computers
Sensitive to technical problems
Distributed architecture
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Cheaper
Less sensitive
Additional cost on hubs and switches
Load-balancing systems
Complex load balancing
QUESTIONS?