introduction to server client

8/2/2019 Introduction to Server Client

1/21

An Introduction toClient/Server Architecture

Dr. Farid Farahmand


2/21

A Brief History: Open Platform

The good old daysOctopus-like mainframesOnly a few venders to choose fromFarms of disks where required

Applications were specific for each machineOpen platformNew client/server architectureOpen system allowed mix-and-match

Different application technologies could bepurchased from different vendersExamples: server platform, client platform,network protocols, middleware software, etc.


3/21

What is Client/Server (C/S)Computing

It started as PCs became more powerfulPCs were no longer dumb terminals

Provided an open and flexible environmentC/S is considered as a form of distributedsoftware


4/21

Distinct characteristics of C/SClient-server is a computing architecture which separates a client from aserverIt is almost always implemented over a computer networkThe most basic type of client-server architecture employs only twotypes of nodes: clients and servers.

This type of architecture is sometimes referred to as two-tier .

It allows devices to share files and resources.Server provides the serviceClient is considered as the customer requesting the serviceThe server service can be shared among a number of clientsClients must request or initiate the serviceThe location of the server in the network is transparent to clientsTransaction between C/S is message-passing based

C/S architecture is scalablehorizontally (more clients can added)Vertically (more servers can be added)

The server is centrally maintained where as clients are independent of eachother


5/21

Systems with C/S ArchitectureFile servers

File sharing and file processingData base servers

Passing file resultsExample: Query in DBMS server Typically one single request/reply

Transaction servers

Transaction server includes DBMS and transaction monitoringServer has remote procedures run online by the clientweb servers

Super-fat servers and thin clientsUses HTTP protocolJava was first to introduce interactive C/S forms

Client

Client

Server

Server

Internet

ClientJAVA

ClientHTML

Application


6/21

Client/Server ModelsWhere to push the application toFat clients

The bulk of the application is running on the clientThe client knows how the data is organized and where it isDifferent clients access the same applications different ways

Fat serversThe server more complicatedThe clients are less complexMore of the code runs on the serverThe network interaction is minimized

ServerClient

Application


7/21

Middleware SoftwareIt is the (/) between client and server which glues them together

Allowing the client request for a service and the serverproviding it

Middleware can also be between server/serverTwo broad classes

GeneralLAN servers, TCP/IP, Communication stacks, Queuing services,etc.

Application specificUsed to accomplish a specific taskGroupware specific: SMTPInternet specific: HTTPDatabase specific: SQL


8/21

Two-Tier vs. Three-Tier Architecture

Same basic idea as fat-client versus fat-serverDepends on how the application is divided between the serverand the clientTwo-tier servers

Examples: file servers and database server

In this case the process (application logic) is buried withinthe client or server (or both)Three-tier servers

Examples: Web and distributed objectsIn this case the process is run on the middle-tier

separated from the user and data interfaceThey can integrate the data from multiple sourcesMore robust and more scalable


9/21

Client/Server Building Blocks

PurposeHow to divide the applicationbetween the client and serverWhat are differentfunctionalities of client andserver

Basic client server modelFits various applications

Small officeSmall businessEnterpriseGlobal

Client

Server

Server

Client ServerMiddleware

Single Machine

Client Server

Middleware

Client Middleware

C/SMiddleware

C/S

C/S

C/S


10/21

Servers and Client Building Blocks

Web Browser

GUIDSM

OS

Service-Specific; DSMNOS (securit, peer-to-peer,directory, distributed files);

Transport stack (TCP/IP)

Web serverGroupware

DMBSEtc.

ClientMiddleware

Server

NOS=Network operating system


11/21

Server Scalability

PC Server

Asymmetric Multi-processing Superserver

symmetric Multi-processing Superserver

Multiservers


12/21

Server ScalabilitySuperserver

A very powerful serverSingle-server or multiserverEach server can have a single processor or multiprocessorMultiprocessing can be Asymmetric or Symmetric

MultiprocessingAsymmetric: each processor is dedicated to a specific taskFully symmetric (SMP): applications are divided into threads and threads are sent to availableprocessors

Examples: 32-bit NT, Unix, NetWareRequires 3 basic functionalities:

Global schedulingI/O sharing structureOS access sharing

MultiserversPool of servers, providing more processing power (also called a cluster)They divide the task between different servers

Server liteAs opposed to full blown serversProvides a background process on the client machine that can accept unsolicited networksrequest (refreshing database, synchronizing time, etc.)


13/21

OS WarsGeneral trends

More powerful PCs (fat PCs, Network PCs, Multimedia PCs)Operating system applications

Embedded devices (cell phones)ClientsSuper clientsServersSMP serversClusters

OS playersDOS and Windows 3.x/95JAVA OSOS/2 Wrap

NT/XP/2000/2003/VISTANetWare (Novells, poor application server, fast file server) UnixLinuxSpecialized parallel OS for clusters


14/21

Client/Server Networking Model

Networking in Linux follows the client/server modelServer provides the resource (web server)Client talks to the server (browser, e-mail program)

Server has a corresponding program thatcommunicates with the client (runs in thebackground)

In Windows the server program called service In Linux the server program called daemon in Linux


15/21

UNIX/Linux

UNIX was introduced in 1969Linux is from the early 1990s

Based on MINIX

Three basic componentsKernel central portion of OSFile system provides input and outputmechanisms

Shell provides user interface


16/21

Linux Introduction

Source code is freely availableDevelopers can make changes

Available from a number of organizations(called disro)

Red HatMandrake

SuSe


17/21

Linux Resource

List of Linux compatible hardware:http://www.linuxquestions.org/hcl/

List of hardware issues and forums for Linuxhttp://www.linuxcompatible.org/

Third-party utilities allowing Windows to read thedrives of a Linux installation on the same machinehttp://pro.mount-everything.com/ http://www.symantec.com/home_homeoffice/products/ overview.jsp?pcid=sp&pvid=pm80
http://www.linuxquestions.org/hcl/http://www.linuxcompatible.org/http://pro.mount-everything.com/http://www.symantec.com/home_homeoffice/products/overview.jsp?pcid=sp&pvid=pm80http://www.symantec.com/home_homeoffice/products/overview.jsp?pcid=sp&pvid=pm80http://www.symantec.com/home_homeoffice/products/overview.jsp?pcid=sp&pvid=pm80http://www.symantec.com/home_homeoffice/products/overview.jsp?pcid=sp&pvid=pm80http://pro.mount-everything.com/http://pro.mount-everything.com/http://pro.mount-everything.com/http://www.linuxcompatible.org/http://www.linuxquestions.org/hcl/


18/21

Fedora LinuxTwo ways to obtain

Installation CDDownload and burn your own CD Read to see how to burn a DVD

http://fedoraproject.org/wiki/Distribution/Download Obtain a copy

http://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/ http://download.fedora.redhat.com/pub/fedora/linux/core/4/i386/iso/

Fedora core 6, i386 Intel x86 processor compatible, first CD ISO imageFC-6-i386-disc1.iso

When you have dowloaded the ISO images, you need to burn them on CD/DVDPopular Windows CD burning tools: http://iso.snoekonline.com/iso.htm You can also use CD BurnerXP Pro http://www.cdburnerxp.se/
http://fedoraproject.org/wiki/Distribution/Downloadhttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/http://download.fedora.redhat.com/pub/fedora/linux/core/4/i386/iso/http://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://iso.snoekonline.com/iso.htmhttp://www.cdburnerxp.se/http://www.cdburnerxp.se/http://iso.snoekonline.com/iso.htmhttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/FC-6-i386-disc1.isohttp://download.fedora.redhat.com/pub/fedora/linux/core/4/i386/iso/http://download.fedora.redhat.com/pub/fedora/linux/core/6/i386/iso/http://fedoraproject.org/wiki/Distribution/Download


19/21

Summary

Got it?


20/21

Homework 1 LinuxMonday

Visit Fedora Core Web cite. What is the latest version ofFedora?Burn a copy of Fedora Core 4 on CDs or DVD. You must havethis in order to install Linux on your machine You are notallowed to do the lab without your own CD.

Search for Linux Commands and obtain a one or two-page longlist of some of Linux commands used with Fedora Core 4versionIn your own words, list 5-10 differences between Fedora Core 4and Fedora Core 7 version. You must tabulate your answer.

Do a little research and briefly explain the sequence involved ininstalling Windows and Linux. What will you do if Windows isalready installed?NOTE: Submit a hardcopy only.


21/21

referenceshttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.html http://www.cisco.com/univercd/cc/td/doc/cisintwk/idg4/nd2011.htm on ISDNLearn about 2-Tier and 3-Tier systems:http://www.sei.cmu.edu/str/descriptions/clientserver_body.html
http://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.cisco.com/univercd/cc/td/doc/cisintwk/idg4/nd2011.htmhttp://www.sei.cmu.edu/str/descriptions/clientserver_body.htmlhttp://www.sei.cmu.edu/str/descriptions/clientserver_body.htmlhttp://www.cisco.com/univercd/cc/td/doc/cisintwk/idg4/nd2011.htmhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.htmlhttp://www.nakov.com/inetjava/lectures/part-1-sockets/InetJava-1.1-Networking-Basics.html

introduction to server client

Documents