Chapter 8
Web Server Hardware
and Software
Learning Objectives
In this chapter, you will learn about:
• Web server hardware considerations
• Measuring the performance of Web server hardware
• The way that individual computers are combined to
provide large-scale Web services
• Web server software including Apache, Microsoft
Internet Information Server, and iPlanet Web Server.
Other software that works with Web server software to
accomplish the basic operations of a Web site.
Web Server Hardware
and Performance Evaluation
• Today a Web site may be the first place customers go
to conduct business with traditional companies, while
electronic commerce sites have become the main
business focus for many organizations.
• The two main ingredients in a Web server are its
hardware and it Web server software.
Types of Web Sites
• An important first step in planning a Web server is to
determine what the company wants to accomplish
with the server.
• The company must estimate how many visitors will be
connecting to the Web site and what types of files will
be delivered through the site.
• Companies create Web sites in a wide variety of forms
including simple development sites, intranets,
information-only sites for customers, business-tobusiness portals, storefronts, or content-delivery.
Development Sites
• The simplest Web site and the least costly to
implement is a development site.
• A development site can reside on an existing PC and
can be developed with low-cost Web site building
tools, such as Microsoft FrontPage or Macromedia
Dreamweaver.
• Testers can access the site through their PCs on the
existing LAN.
Intranets
• Corporate intranets house internal memos, corporate
policy handbooks, expense account worksheets,
budgets, newsletters, and a variety of other corporate
documents.
• Intranets are shielded from the Internet, they do not
require additional security software to protect them
against threats from outside the company.
Transaction-Processing Sites
• Transaction-processing sites, such as business-tobusiness and business-to-consumer electronic
commerce sites must be available 24 hours a day,
seven days a week; that is, they must be highreliability servers.
• Transaction-processing sites must also have spare
server computers to handle high traffic volumes.
• Transaction-processing sites must also run security
software.
Content Delivery Sites
• Content delivery sites, such as The Wall Street
Journal, The New York Times, and C-Net, sell and
deliver content, such as news, histories, summaries,
and other digital information.
• Content must be presented rapidly on the visitor’s
screen.
• Visitors must be able to locate articles quickly with a
fast and precise search engine.
Web Hosting Choices
• The company must decide whether to run servers
in-house or through third-party Web and e-commerce
providers.
• Companies should consider:
– scalability of e-commerce
– bandwidth of the Web site
– a local third-party ISP
• Contact Web Host Guild (WHG) for help.
Web Hosting Choices
Web Hosting Choices
• When making Web server hosting decisions, a
company should ask whether the hardware, or
platform and software combination, can be upgraded
when the traffic on its site increases.
• Using a service provider’s shared or dedicated
hosting services instead of building an in-house
server or using a co-location service means that the
staffing burden shifts from the company to the Web
host.
Web Hosting Choices
Operating Systems for Web Servers
• Hardware decisions go hand in hand with operating
system and application server software choices.
• Companies should consider:
– Speed -- A fast server is better than a slower one
– Internal and external traffic to occur on the server
– Scalability of the server hardware
Test Reports on Various Web Servers
Building a Scalable E-commerce
Systems
• Three layers in E-commerce systems:
• Web server layer
• Middle-tier layer
• Backend layer
• An application server is a middle-tier software and
hardware combination that lies between the Internet
and a corporate backend server.
Web Server Performance Evaluation
• Benchmarking is a form of testing used to compare
the performance of hardware and software.
• Hardware and operating systems are key areas for
benchmarking.
• The speed of its connection can affect a Web server’s
performance.
• Throughput and response time can be used to
measure a server’s Web page delivery capability.
Web Server Benchmark Software
• Web server benchmark software types are listed
below:
– NetBench
– ServerBench
– SPEC SFS97
– SPECweb99
– WCAT
– WebBench
– WebStone
Desirable Features of Web Servers
• Web servers are located on the Internet or intranets,
usually behind firewalls.
• The duties and features of Web servers differ
depending on whether they are publicly accessible.
• Web server software features depend on the software
package being used.
Core Capabilities
• The most fundamental duty of a Web server is to
process and respond to Web client requests that are
sent using the HTTP protocol.
• For dynamic pages, the server uses an architecture
with three or more tiers that invokes other programs.
Indexing and Searching
• Search engine and indexing programs are important
elements of many Web servers.
• Search engines, or search tools, search either a
specific site or the entire Web for requested
documents.
• An indexing program can provide full-text indexing
that generates an index for all documents stored on a
server.
Data Analysis
• Web servers can capture visitor information, including
data about who is visiting a Web site, how long the
visitor’s Web browser viewed the site, the date and
time of each visit, and which pages were displayed.
• Two of the most popular Web log file analysis
programs are the Analog Web server log file analyzer
and the WebTrends Web server log file analyzer.
• Figure 8-4 shows part of WebTrends log file analysis
report.
Data Analysis
Site Management Tools
• FrontPage has some site management capabilities.
• HomeSite is a site management tool that validates
graphics, computes page-download times for modem
connection, validates links, and validates HTML
codes.
Site Management Tools
• Application construction uses Web editors and
extensions to produce Web pages.
• Some Web development systems provide simple tools
to create Web pages.
• Some tools can be used to create dynamic features
without the need to know CGI or use API coding.
Link Checking
• A link checker examines each page on the site and
reports on any URLs that are broken, that seem to be
broken, or that are in some way incorrect.
• An orphan file is a file on a Web site that is not linked
to any page.
• Other important site management features include
script checking and HTML validation.
• A dead link, when clicked, displays an error message
rather than a Web page.
Link Checking
• Free link-checking and Web site validation programs,
such as Elsop Linkscan, can be launched by entering
the address of a Web site’s home page and checking
a few boxes.
• Commercial site checkers, such as Big Brother
software from Watchfire, produce more
comprehensive results and more detailed site
analyses than do the free products.
Link Checking
Remote Server Administration
• With remote server administration, a Web site
administrator can control a Web site from any
Internet-connected computer.
• Although all Web sites provide administrative
controls, it is convenient for an administrator to be
able to fix the server from wherever he or she
happens to be.
Remote Server Administration Tool
Dynamic Content
• Dynamic content is nonstatic information constructed
in response to a Web client’s request.
• Using Open DataBase Connectivity (ODBC), the Web
server can assemble information from disparate
database systems.
• Active server pages (ASP) is a server-side scripting
mechanism to build dynamic sites and Web
applications.
Dynamic Content
• Most Web sites today provide dynamic Web pages
using an approach called server-side scripting.
• In server-side scripting, programs running on the Web
server create Web pages before sending them back to
the requesting Web clients as parts of response
messages.
• Microsoft uses Active server pages (ASP).
• Sun uses Java server pages (JSP).
• Apache developed Hypertext Preprocessor (PHP).
Web Server Software
• There are two distinct Web servers in the market:
intranet servers and public Web servers.
• Three of the most popular Web server programs are:
• Apache HTTP Server
• Microsoft Internet Information Server
• Netscape Enterprise Server
Apache HTTP Server
• The Apache HTTP Server is free and performs
efficiently.
• Apache runs on many operating systems and the
hardware that supports them.
• Apache has a built-in search engine and HTML
authoring tools and supports FTP.
Apache HTTP Server
• Apache can be managed from either a server console
or a Web server.
• Apache supports Server Side Includes (SSI), Active
server pages and Java Servlets.
Microsoft Internet Information Server (IIS)
• IIS comes bundled with Microsoft’s Windows NT
Server and 2000 Server operating systems.
• IIS includes an integrated search engine.
• IIS supports FTP, permits administration from a
remote browser.
• IIS combines HTML pages, ActiveX components, and
scripts to produce dynamic pages.
Microsoft Internet Information Server (IIS)
iPlanet Enterprise Server
• The iPlanet enterprise server runs on such operating
systems as AIX, Digital UNIX, HP-UX, Irix, Solaris, and
Windows NT.
• iPlanet Web server provides a powerful development
environment that supports development of Webbased applications that can run on the Internet, an
intranet, or an extranet.
• iPlanet Web server’s management tools allow
administrators to manage users and monitor server
activity interactively.
iPlanet Enterprise Server
Determining Web Server Hardware and
Software Information
• You can determine the type of hardware and software
most Web sites are running by visiting Netcraft.
• Netcraft software examines the designated Web site
and returns both the Web server hardware and
software information.
Determining Web Server Hardware and
Software Information
Server Architectures and Server Utilities
• Companies that operate more than one Web server
must decide how to configure their servers to provide
site visitors with the best service possible.
• The different ways that servers can be connected to
each other and to related hardware, such as routers
and switches, is called server architecture.
Web Server Architectures
• Large electronic commerce Web sites must deliver
millions of individual Web pages every day.
• They must also process thousands of customer and
vendor transactions each day.
• The large collection of servers that these sites have
are called server farms.
Web Server Architectures
• One approach to Web server architecture is called a
centralized architecture, which uses a few very large
and very fast computers.
• Another approach is a decentralized architecture,
which uses a large number of servers.
• Most large decentralized sites use load-balancing
systems.
Load-Balancing Systems
• A load-balancing switch is a piece of network
hardware that monitors the workloads of the servers
attached to it and assigns incoming Web traffic to the
server that has the most available capacity.
• In a simple load-balancing system, the traffic that
enters the site from the Internet, encounters the loadbalancing switch, which then directs the traffic to the
Web server best able to handle the traffic.
Load-Balancing System Architecture
Complex Load-Balancing
Search Engines
• A search engine is a special kind of Web page
software that finds other Web pages that match a
word or phrase you entered.
• A Web directory is a listing of hyperlinks to Web
pages that is organized into hierarchical categories.
• Search engines contain three major parts: spider,
index, and utility.
Intelligent Agents
• Software agents have been in use for a number of
years.
• An intelligent agent is a program that performs
functions, such as information gathering, information
filtering, or mediation running, in the background on
behalf of a person or entity.
• Research reveals that software agents will become
extremely important in the electronic commerce field
sooner than later.
Intelligent Agents
• Because software agents are always running in the
background they can help reduce the workload that
people normally take on in locating, thinking about,
negotiating, and purchasing goods and services.
• Examples of agent systems include Best Web and
MySimon.