5 chapter five web servers. 5 chapter objectives learn about the microsoft personal web server...

5 ChapterFive

Web Servers

5 Chapter Objectives

• Learn about the Microsoft Personal Web Server Software

• Learn how to improve Web site performance

• Learn about absolute and relative URL addresses

• Compare Personal Web Server to other Web servers

5 Web Servers

• Web servers are computers connected to the Internet and run special Web server software

• Software includes a component called a listener, which monitors for Web page requests that are sent to the Web server from client browsers

5 Web Servers

• When a browser requests a particular Web page from a Web server, the Web server sends the HTML file for the Web page to the client browser

• The Web server also processes server-side programs that create dynamic Web pages

5 Personal Web Server

• Personal Web Server (PWS) is software– Designed to create and manage a Web server,

also called a Web site, on a desktop computer

– Used to learn how to set up and administer a Web site

– Used as a site for testing dynamic Web pages


• A visitor is a user who uses browsers to make connections and request Web pages

• PWS can support only 10 Web server connections at one time– A Web server connection corresponds to a

socket on the Web server– A socket is an endpoint of a communications

connection


• Each connection between a client and server creates a socket on both the server and client

• Each socket has a corresponding memory location that specifies information about the connection

• Each Web server socket also has another corresponding memory location that stores incoming data requests from the user’s Web browser


• To make Web pages appear faster, many Web browsers can create up to four simultaneous connections to a Web site

• PWS Web sites cannot service requests from more than two or three simultaneous visitors in a timely manner


• Production Web server – A Web server that can be accessed by anyone

connected to the Internet

• Personal Web Manager – A PWS utility – Allows you to modify the configuration of

PWS


Figure 5-1: Personal Web Manager Main page


• Main page– Shows the URL for your PWS, and drive letter

and folder path to PWS’s root document folder

• Publish page and Web Site pages– Have wizards that automate the process of

creating and editing HTML documents and creating links to documents


• Tour page – Provides a basic overview of PWS

• Advanced page – Allows you to specify the Web server’s root

document directory and default document filenames, and to configure other Web server properties


Figure 5-2: Advanced Options page

5 The Web Server Root Document Directory and Default Document

• Root document folder– Central folder containing all Web pages, graphic

images, programs, and other files available from the Web site

• When a visitor specifies in his or her Web browser a URL that contains a Web server domain name or IP address, but no HTML Web page filename, the server returns the HTML document that has been specified as the Web server's default document


• To make Web pages appear faster, most Web browsers are configured to cache, or save, recently viewed Web pages on the local hard drive

• Every computer that connects to the Internet must have a unique IP address


• Some computers have static IP address, which are IP addresses that:– Never changes and refers only to a specific computer– Are assigned to computers that stay in the same

physical location or computers that are servers

• Dynamic IP address– Assigned to a computer from a list of available

addresses each time the computer is booted and its Internet access software is loaded

– Might change each time the computer is booted

5 Directory Browsing

• Directory browsing – Allows Web site visitors to use a folder listing

to navigate to different files on the Web server– When enabled, PWS will display a list of all

files in the root document folder if the default document file is not specified or found

5 Directory Browsing

Figure 5-4: Listing of PWS root document folder contents

5 The Web Site Activity Log

• Web Site Activity Log – Maintains a list of the IP addresses of computers

that connect to your Web site

Figure 5-6: Web Site Activity Log file


• Log file– Contents can be viewed using any text editor or

word processor

Figure 5-7: Log file contents


• When using IP addresses in the log file to identify who is accessing your Web site:– Visitors with dynamic IP addresses usually

cannot be identified– Visitors with static IP addresses and associated

domain names can sometimes be identified, using a utility named Nslookup


Figure 5-8: Using Nslookup to find the identity of a Web site visitor


• Information about domain names can be located using Web-based services that maintain information about domain names

Figure 5-9: Information about a Web site visitor’s domain name

5 Creating Virtual Directories

• Virtual directory – Folder that does not have to be physically within the

root document folder, but always appears to client browsers as though it is

• Alias– Name client browsers can use to access that directory– Usually shorter than the folder pathname – More secure since visitors do not need to know the

names of folders where your server files are located


Figure 5-10: Virtual directory properties


Figure 5-11: Folder listing of a virtual directory


Figure 5-12: Creating a virtual directory

5 Managing Virtual Directory Access Privileges

• Read access– Enables a visitor’s Web browser to read or

download files stored in virtual directory

• Execute access – Enables Web clients to run compiled

(executable) Web applications as well as server-side scripts stored in a virtual directory


• Scripts access– Enables a visitor’s browser to run only scripts that

are stored in the virtual directory, not executable programs

Table 5-1: Virtual directory privilege types and associated file types


Figure 5-13: Creating the cgi-bin virtual directory

5 Monitoring Web Site Performance

• Monitoring section of Personal Web Manager Main page allows you to monitor statistics about visits to your Web site

• Data are collected about the following items:– Active connections, Started at, Visitors,

Requests, Bytes served, and Most concurrent connections


• Active connections – Represents number of active server connections

currently being used to transfer data to visitor browsers

• Started at – Shows when the server was last started

• Visitors – Shows number of unique IP addresses connected to

the server since the workstation was last started


• Requests – Shows number of requests received since the computer

was last restarted

• Bytes served – Shows total amount of data sent since last restart

• Most concurrent connections – Shows number of connections opened to the server

simultaneously since the computer was last started


Figure 5-14: Viewing the monitoring statistics

5 Factors Affecting Web Site Performance

• Factors affecting time it takes a Web site to service a visitor request include: – Speed of the Web server’s network connection– Amount of main memory that a Web server has

allocated to process Web page requests– Web server’s processor speed

5 Factors Affecting Web Site Performance

• Factors affecting time it takes a Web site to service a visitor request include (cont.):– Number of other visitors currently requesting

Web site pages or files– Size of Web page files and number and size of

their embedded graphic object files– Resources needed by Web-based programs and

scripts in Web pages

5 Referencing Files on a Web Server

• When referencing an object on a Web page that is stored on a Web server, the referenced object must be in same folder as the Web page that is currently displayed

• Saving copies of all Web pages and their associated graphic objects in multiple folders on a Web server is not an effective way to use disk space

5 Referencing Files on a Web Server

• When you change a Web page HTML file, you might not remember to update all the copies of the page file if they stored in multiple places

• A better way to manage referenced objects is by specifying object locations using absolute or relative URL addresses

5 Absolute URL Addresses

• Absolute URL address– Can be used in browser’s Address box or in a

hyperlink tag to specify complete path location of a Web page file

– Includes the Web server IP address or domain name, the complete folder path or virtual directory path to the Web page file, and the name of Web page file

5 Absolute URL Addresses

Figure 5-15: Absolute URL addresses

5 Relative URL Addresses

• Relative URL address– Specifies the location of a file relative to the

current working directory

Table 5-2: Relative path addresses

5 Comparing PWS to Other Web Servers

• PWS– Supports the most common server-side

programming approaches that can be used with production Web servers

– Can run CGI programs or scripts and Active Server Pages (ASPs)

• IIS – More sophisticated administrative features


• Internet Service Manager (ISM) utility within IIS:– Supports directory browsing that can be

enabled or disabled for specific directories rather than for the entire Web site

– Provides Write access for virtual directories • Allows visitor browsers to upload and download

files to a Web server


• Internet Service Manager (ISM) utility within IIS (cont.):– Allows the Web server administrator to tune the

Web site for number of expected hits per day– Provides a higher level of security through NT

file system permissions

5 Summary

• Personal Web Server (PWS) is software designed to create and manage a Web server on a desktop computer

• Personal Web Manager is a utility used to configure and monitor PWS

• Personal Web Manager is used to specify the Web site root document directory, and the name of the default document

• PWS support directory browsing

5 Summary

• A Web browser’s current working directory is the folder that contains the Web page that is currently displayed

• PWS provides an excellent environment for learning about Web servers, and for testing Web programs and new Web pages

5 chapter five web servers. 5 chapter objectives learn about the microsoft personal web server...

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