Web server basics Software for Web servers E-mail management and spam control issues Internet and Web site utility programs Web server hardware

2

The main job of a Web server is to respond to requests from Web client computers

There are 3 components of a Web server:

◦ Hardware

◦ Operating system software

◦ Web server software

3

Development sites: Used to evaluate different Web designs Intranets: Corporate networks that house internal memos,

corporate policy handbooks, and a variety of other corporate documents

Extranets: Intranets that allow authorized parties outside the company to access information stored in the system

Transaction-processing sites: Commerce sites that must be available 24 hours a day, seven days a week

Content-delivery sites: Deliver content such as news, histories, summaries, and other digital information

4

Client/server architectures

◦ Client computers request services

◦ A server processes the clients’ requests

Web software is platform neutral, meaning that it lets different types of servers communicate with a variety of clients

5

Dynamic content is nonstatic information constructed in response to a Web client’s request

◦ Dynamic page: Web page whose content is shaped by a program in response to user requests

◦ Static page: An unchanging page retrieved from disk

6

Server-side scripting (or includes)◦ Programs running on a Web server create Web pages

before sending them back to the requesting Web clients Dynamic page-generation technologies: Server

side scripts are combined with html tags to create dynamic content◦ Active Server Pages (ASP)◦ JavaServer Pages (JSP)◦ PHP: Hypertext Preprocessor (PHP)

7

Server ◦ Computer used to provide files or make programs

available to other computers Server software: Used by a server to make files and programs

available to other computers Database server: Server on which database management software

runs

8

Two-tier client/server architecture has one client and one server

9

Request message: Message that a Web client sends to request a file or files from a Web server◦ Typical request message contains:

Request line Contains a command, the name of the target resource, and the

protocol name and version number Request headers

Can contain information about types of files that the client will accept in response to a request

Entity body Used to pass bulk information to the server

10

Three-tier architecture◦ Extends two-tier architecture to allow additional processing (e.g.,

collection of data from a database) before reponses to requests are made

N-tier architectures◦ Higher-order architectures

◦ Third tier includes software applications that interactively supply and update information to and from the web server

11

12

Operating system tasks include running programs and allocating computer resources◦ Open-source software: Developed by a community of

programmers who make it available for download at no cost Linux: Open-source operating system that is easy to install, fast,

and efficient

13