CHAPTER 2CLIENT/SERVER COMPUTING

Client/Server Components

Operating System

Is an important program that runs on every computer.

Acts as an intermediary and allows communication between hardware and software.

Is a system software comprising fundamental files needed to boot up and function ones computer.

Performs basic task such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories, controlling peripheral devices etc.

Operating System

Makes sure that different program and users running at the same time do not interfere with each other.

Is also responsible for security, ensuring that unauthorized users do not get access to the system.

Services of OS

Following are the main services of OS

Carrying out commands of user and the application programs

Supervising installation and running of other programs and hardware

Controlling the input output functions

Allocating system resources such as memory, processor time, disk space and peripheral devices to regulate the flow of work within the computer

Services of OS

o Handling file and directory management

o Providing file sharing and networking functions

Classification of OS

Multi-user allows two or more users to run the programs at the same time. E.g. a Unix server where multiple remote users have access to

the Unix shell promptMultiprocessing

Supports running a program on more than one CPUMultitasking

Allows more than one program to run concurrentlyReal Time

Responds to input instantly. A common example of RTOS is and HDTV receiver and display

as it needs to read a digital signal, decode it and display it as the data comes in.

Network Operating System

Is a computer operating system that are designed primarily to support workstation, personal computer and in some instances older terminal connected through LANs.

Is a software that allows multiple computers to communicate, share files and hardware devices with one another.

Provides services to clients over network

E.g. Novell NetWare, Microsoft Windows NT, Sun Solaris, Linux etc

Services of NOS

Both the client/server and peer to peer networking models uses network operating system and such a system must be able to perform following duties.

Providing access to remote devices, managing which users are using which device and when

Enabling and managing access to files on remote system and determining who can access what and who can’t

Granting access to remote applications and resources such as internet and making those resources seem like local resources to the user

Services of NOS

Providing routing services so that the operating system knows what data to send where

Monitoring the system and security so as to provide proper security against viruses, hackers and data corruption

providing basic administrator utilities, enabling an administrator to perform task involving managing network resources and users.