Chapter 15: Clients and Servers


Overview

Client/server networks have been implemented by UNIX users around the world in order to perform functions that older mainframe systems cannot do efficiently, such as sharing files and resources across a network, and accessing and updating data simultaneously by a number of users on networks using different protocols. File sharing is an important concept in a networked computing environment. When multiple users need access to common information, it is easier and more economical to create one file containing the information, and let everyone share it. While writing information into the common file requires a little coordination, reading information from it only requires that you are allowed access to the file by the machine that houses it.

UNIX plays a key role in client/server computing. In particular, UNIX has been the leading choice of operating systems for servers, and UNIX workstations and PCs are two of the different types of clients these servers serve.

This chapter describes what client/server computing is, how it evolved, and why it is important. You’ll learn the types of things that you can do with client/server computing in a UNIX environment, such as accessing and printing files, or requesting and providing web services for World Wide Web users. The concepts of a web client and a web browser are discussed later on in this chapter; you can find out more about how these two work together on the Internet by reading Chapter 10.

We will also discuss in this chapter how file sharing among users is a key enabler of client/server computing. Tools such as the Network File System (NFS) allow clients to share files with servers in a well-managed environment. The administration of these file system services, using a tool called NIS+ (Network Information Services Plus) is discussed briefly here and also in Chapter 17. NIS+ provides a secure way to ensure that authorized users can access needed f iles f rom the server. You will see some of the same concepts discussed in both this chapter and Chapter 17. This chapter’s focus is primarily on the establishment of file sharing services that are used in a client/server environment. Chapter 17 addresses file sharing as one of a number of issues that a network administrator must manage successfully.




UNIX. The Complete Reference
UNIX: The Complete Reference, Second Edition (Complete Reference Series)
ISBN: 0072263369
EAN: 2147483647
Year: 2006
Pages: 316

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