client server technology
TRANSCRIPT
Client Server Technology
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UNIT -1
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Definition
Client requests to the server for data or
information
Server serves the data or information
Fulfils the requirements of the client & sends
the results back to the client
Client performs some logical operations
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Definition
Client Server Computing (CSC) is that Server Operating
System (OS) accepts requests for data from Client OperatingSystem & returns the results(services) to the Client.
Client manipulates or calculates data and presents the results
to the user.
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What is Networking?
Connecting computers so that they can share
files, printers, applications, and other computer
related resources.
Advantages:-
File server
Network printer
Application servers
Centralized servers
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Different types of networks
Local Area Networks(LAN)
Wide Area Networks(WAN)
Metropolitan Area Network(MAN)
Internet
Different types of Networking
Peer-to-Peer Networking
Workgroup Networking
Server-based Networking
Terminal-based Networking
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History
1969, the Department of Defence USA built
ARPANet(Advanced Research Project Agency).
For sharing of data research centres.
ARPANet started with just 4 computers on the network
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University Of Los
Angeles
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History
ARPANet converted into:
-MILNET – Military Network – which was only for the military
network.
New smaller ARPANet, which had the non military sites.
1971, 2 dozen sites attached to ARPANet.
1972, 40 different sites attached to ARPANet.
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History
1980, another network called CSRNet – Computer Science
Research Network was linked to ARPANet.
CSRNet was created to connect several independent
networks.
This was the birth of internet and networking
1986, the NSF built own network National Science Foundation
(NSF)Net which was also linked to other main networks.
Powerful network in terms of speed
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History
Networking Technology developed, new networks all linked
to the ARPANet, Computer Science Research Network
(CSRNet) and NSF Net.
Networks connected together is known as the ‘Internet’.
ARPANet was finally shut down in 1989
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Evolution of Client
Server Concept
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Evolution
Evolution [growth] of networking
Various reasons can be broadly categorized into following:
1. Hardware Trends
2. Software Trends.
3. Networking Trends.
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Hardware Trends
Hardware Trends can further be divided into the
following:
-Power/Speed
-Chips [Micro Processor]
-Memory
-Storage Devices
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-Power/ Speed 17
-Chips
Chips used were 386, 486 [in MHz].
Now a days chips are available in GHz such as 1.0,2.0,
1.2,1.4,1.7,2.0, Xeon etc..
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-Chips
AMD’s powerful chips Athlon, Pthlon,
Sympthon etc.,
Processors are categorized:-
P1 -> 33Mhz ---166 Mhz.
P2 ->200Mhz ---450Mhz.
P3 ->500Mhz ---1.4Ghz.
P4 ->1.7Ghz --- 2.0,2.1,2.4,Xeon, AMD’s
[Athlon, Pathlon].
i3, i5, i7 -> 1.7Ghz --- 3.3Ghz
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-Memory 20
Memory
Hard Disk Drive
(H.D.D)
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RAM for different Processors
Extended
Data Output
(EDO)
Static
Dynamic (SD)
Dual Data
Rate(DDR)
DDR3
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Storage Devices
Storage devices categorized into two main types:
1. Fixed Storage Devices.
-H.D.D
-Floppy Disk Drive
-Compact disk (C.D) Drive
-Digital Versatile Disk (DVD) Drive
2. Removable Storage Devices
-Pen Drive
-Universal Serial Bus (USB) Hard Disk
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Storage Unit
4 Bits = 1 nibble
8 Bit =1 byte
1024 byte = 1KB [ Kilo byte ]
1024 KB = 1MB [ Mega Byte ]
1024 MB = 1GB [Giga Byte ]
1024 GB = 1TB [ Tera Byte]
1024 TB = 1 PB [ Pera Byte ]
1024 PB = 1 Exabyte
1024 EB = 1Zettabyte
1024 ZB = 1 Yottabyte
1024 YB = 1 Brontobyte
1024 BB = 1 Geopbyte
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Software Trends
1. Graphical User Interface (GUI) Concept.
2. RDBMS.
3. Multi Threading Processing.
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1. GUI concept
GUI is Graphical User Interface.
WYSWYG [What You See is What You Get].
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2. RDBMS
RDMBS is Relational DataBase Management System.
Manage & Maintains Large DataBase.
E.g. Oracle, FoxPro, SQL, MS Access.
Data is stored in Tabular format.
Development in C/S or networking, it is possible for various
users to access the same data at a time.
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2.RDBMS 28
3. Multi-Thread Processing
A thread is the smallest unit of process or an execution
Multithreaded S/w such as Microsoft LAN manager Network
Operating S/w MS 2003 Server…etc.
Support multiple threads of execution the printer, one the
keyboard I/O and another executing application code.
Multithreading support allows the S/w to make more
efficient use of the H/w.
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Networking Trends
Connects two or more computers for data or
device sharing is known as networking.
Network is an Inter Process Communication (IPC)system in which data or message transferred b/w
process and threads
Network Architecture has rules and protocols for
how transfer occurs within the architecture
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Networking Trends
Different H/w and S/w can communicate as long
as they use the same protocols and data
formats.
The earliest micro LAN’s were easy to install.
Provides Security and Authentication of Data
Access.
Categories are LAN, WAN, MAN or Virtual Private
Network (VPN)
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Advantages of
CST computing/
need & motivation
for C/S Approach
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Advantages
Networking plays a very important role.
It is life line of today’s modern offices.
LAN to intranet to internet.
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Advantages
Connectivity.
Sharing Devices.
Flexibility and Scalability.
Centralized Control.
Faster Delivery of Systems.
Resource Utilization.
Reduction in Network Traffic.
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Advantages -Connectivity
Connectivity is to connect other computers or resources.
Provides the interactivity share our data or information among
multiple computers.
We can also share our files on the network.
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Advantages -
Connectivity
‘File Sharing’
‘Resource Sharing’
‘Remote Accessing’.
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Advantages -Connectivity
Accessing a Remote Computer through Network
All these facilities are provided by the ‘Network
OS’ or the ‘Server OS’.
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Advantages -Sharing
Devices In CST we share various devices
Sharing of resources is done through networking
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Advantages -Flexibility
and Scalability Segmenting the application task, an organization can easily
add a new technologies.
Enhance existing technologies without interruption
Add a new computer or node on a network also removed.
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Advantages -Flexibility
and Scalability
Add or remove Computers
Data access through networking is easy
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Advantages -Centralized
Control
Centralized facility is the one in which data is
transmitted through channel.
In past centralized facility was difficult toimplement and maintain.
Client Server Technology (CST) allows facilities to
combine Centralized and Decentralized
Architectures.
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Advantages -Centralized
Control Decentralized portion of the system consists of the
processing done on the client and is the
responsibility of the business and user.
Centralized portion of the system consists of the
processing performed on the server and is the
responsibility of Internet Securities professional as
are the link to the server.
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Advantages -Centralized
Control Server maintains an Intelligent Database with rules and
security
E.g.: Backup and Recovery procedures are centralized
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Advantages -Faster Delivery of
Systems Workstation environment, powerful multitasking CPU
availability, single user database and integrated testing tools.
All combine to provide the developer with considerable
productivity improvements in a lower cost environment.
Server application functionality, database, and network
services is transparent and almost automatic.
Network components & communication channel or media
are helpful to perform faster delivery on networks.
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Advantages -Reduction in Network
Traffic Excessive network traffic is one of the most common causes
of poor system performance
Designers take special care to create to a avoid such
situation
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Reduction in Network
Traffic
In client server model, it is possible to reduce the
network traffic and
Provide frequent transmission of data between computers through a routers and fiber optic
cable.
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Client Server
Environments
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The Environments
Client Server is a network architecture.
Components: The Client and The Server.
Client runs an application using Graphical
Interface (G.I)
Through this application can request the Server.
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The Environments
Server accepts the request and responds.
Servers are classified as Web Servers, File Servers, Terminal
Servers, Mail Servers etc.
Servers may have different size, OS or different purpose
Basic architecture remain same
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The Environments
Example of CS Technology is the internet
Internet are stored on a Server machine
User requests for the application to the Server
Server searches
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Characterization
of Client/Server
Computing
COMPONENTS OF CLIENT SERVER TECHNOLOGY
/ COMPUTING
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Components
There are mainly three components.
1. The Client
2. The Server
3. The Network
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The Client
Client is the desktop machine
Micro or Workstation computer
Network s/w sends the request to the server
Accepts result form Server and passes result back to Client
Client may perform some application logics
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The Server
Server machine is designed for server
functionality
Comparison to desktop machine
Increased Memory capabilities
Increased Storage capabilities
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The Server
Increased processing power [ through multi
processor technology].
Improved Reliability with built in reliability featuressuch as:
-Uninterruptible Power Supply
-Fault Tolerance
-Disk Mirroring
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The Server
Evaluating server h/w:-
1. Reliability
2. Availability
3. Flexibility
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1. Reliability
Server Machine is considered as brain of
networking
Directly or Indirectly controls whole network
Responsible for speed and performance of
network
Server machine has to be very reliable
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1. Reliability
The reliability is checked by the fact that how
often does it fail?
What is the mean time between failures?
Does it perform automated regular data
backups?
Does it has any strategy to deal with power cuts?
All these questions and many important features
of server make it a reliable machine.
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2. Availability
Availability refers?
Systems have self healing routines
Fault tolerant alarms
Specific configuration rebooted from a remote
site
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Flexibility & Scalability
The application tasks, an organization can easily
migrate to new technologies or enhance existing
technologies with or no interruption
Application does not have to be redesigned to
use a new interface s/w or be moved to new
platform
We can always add a new computer or remove
a node from the network
Data access through networking is also very easy
through a GUI
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3. The Network
Network connecting devices
Managed and maintained by network
Managed I/O processes
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2. Distributed Working
Distributed computing is a method of computer
processing
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The Role of
ClientUNIT II
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The Client
Request to Server
Network Operating System(NOS) Software who
helps in making the request and forwarding therequest to the server
NOS software translates or adds the specifics
required
IPC (Inter Process Communication).
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The Client
Processes might be on the same computer
Service provided by the NOS is redirection.
Service intercepts client workstation Operating
System(OS) calls redirects them to the Server OS
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The Client
Request for files, printers, serial devices,
application programs
Redirected to the correct server location.
Possible for some services to provided by the
client workstation.
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The Client
Local disk drivers may be labelled A: or C: and the
remote drives by label Z:, D: or anything else.
How does redirection works ?
Requests for drive A: or C: is passed through to the
local file system by the redirection software.
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The Client
Requests for other drives are passed to the server
operating system.
Printers are accessed through virtual serial ports
NOS requester software constructs the Remote
Procedure Call.
Application programming interface (API) calls to
the NOS server.
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The Client
NOS server then processes the request as it is were
executed locally and response back to the
application.
Novell commercialized this redirector concept for
the INTEL and MS DOS platforms and it has been
then adopted by all NOS.
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Dynamic Data Exchange
(DDE)
Provides automatic information exchange
It provides the linking
Windows alternatives to DDE
DDEML stands for Dynamic Data Exchange Management
Library
Provides better interface then DDE
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DDE
Mediator b/w called and calling app
Calls for services are made to DDEML
Passes data b/w application from different
vendors
Example- Chart from excel can be linked to a
database to provide the latest data whenever
the chart is referenced.
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Dynamic Link Library(DLL)
File containing executable routines that can be
loaded on demand by an application.
Providing standard services for many different calling applications
DLL are loaded into RAM only when needed by
the calling application
DLL are files that have the extension .dll
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Object Linking &
Embedding
Technique or Concept which you can link or
embed the object with one another
Allows user to build compound document
Document is treated as a Collection of objects
rather than file
Double clicking on an object starts up the original
application software and allows the user to
modify the object.
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Object Linking &
Embedding
Create and edit documents by using different
applications
For example you can embed bitmap images, sound clips, spread sheet files and other objects in
Microsoft Word documents.
Basically this feature provides us with ‘Linking’ and
‘Embedding’
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Object Linking &
Embedding
Linking:-
A link is added in a document
Link points to the source data stored somewhere
Linked objects are stored in the document as a
path to the original linked data
Changes in the data will be reflected in the
original data also.
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Object Linking &
Embedding
Embedding:-
Embedding adds one document directly into
other document
Embedded objects are stored with the document
that contains them
Change in the data in embedded file is not
reflected in the original data
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CORBA
‘CORBA’ stands for Common Object Request
Broker Architecture
Component architecture developed by the Object Management Group and its member
companies.
Technology for creating, distributing and
managing component programming
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CORBA
Designed to provide interoperability b/w
applications in heterogeneous distributed
environments.
CORBA is not supported by Microsoft
Instead has developed its own distributed object
management architecture
The architecture developed by MS is called
COM(Component Object Mode) or
DCOM(Distributed COM)
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HOW CORBA works?
Requests service through an Object Request
Broker (ORB)
ORB allows components of distributed applications
Applications communicate without knowing
where the application is located in network
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HOW CORBA works?
ORB’s are in fact the middleware s/w that enables
client and server programs to establish session
with each other.
Independent of their location in the network or
their programming interface
Client issues a call which is intercepted by the
ORB
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HOW CORBA works?
ORB takes call and is responsible for locating a
server machine that is able to process the request
Once it has located the server, it invokes the object’s methods and passes any parameters
submitted by the client
The requests are then processed and the result is
sent back to the client
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HOW CORBA works?
ORB’s communicate among themselves using
GIOP(General Inter ORB Protocol)
They also Communicate through the IIOP(Internet Inter ORB Protocol).
So ORB’s can fulfill the request of any client
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CORBA vs OLE
CORBA is specification of Object Management
Group(OMG)
OLE (Object Linking Embedding) focuses on data sharing b/w applications on a single desktop
CORBA addresses cross platform data transfer
and moving object over networks
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CORBA vs OLE
CORBA support enables windows and UNIX clients
to share objects.
A word processor operating on Windows platform can include graphics generated from UNIX
workstation.
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RPC(Remote Procedure
Cell)
Message passing programming technology
developed by Sun Microsystems and extended by
the Open Software Foundation (OSF)
Applications to execute procedures and interact
with services on a remote computer on network
CST on MS windows server 2000 and window NT
platforms is enabled using RPC’s
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How it works?
RPC is to pass messages b/w components of a
distributed application that are located on
different computers on a network.
Local Procedure Calls(LPC’s) provide a
mechanism for enabling different parts of an
application located on a single computer to
communicate with each other.
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How it works?
RPC’s provide a mechanism through which
computers on different networks can
communicate with each other
In fact RPC’s use a wide variety of IPC
mechanisms such as NetBIOS (Network Basic Input
Output System), windows sockets, mail slots to
establish connections between the RPC client
and the RPC server
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How it works?
The Remote Procedure Call service (RPC service)
is a component of the Windows NT executive
running in kernel mode
It is responsible for message passing b/w the client
and the server components of a distributed
application
Message is passed b/w client server application
such as MS outlook express and MS exchange
server
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How it works?
On a windows NT based network the server first
registers itself with the RPC Locator service
The client part of the application which is on the local computer can then query the RPC locator
service to determine the location of the required
server part.
The RPC server located server is a part of the
operating system located on the client machine.
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How it works?
A process called the remote procedure stub then
packages the clients function call into a suitable
RPC message and sends it to the remote computer using RPC run time process
At the remote machine a process called the
application stub receives the RPC message
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How it works?
It unpackaged the message into a function call
and executes it, returning any resulting values to
the client part in a similar fashion.
From the view point of the client part of the
application, the server part appears to be on the
same computer.
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CST Application
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CST Applications
Applications that run on a network, technically
different from application running on a local
machine.
Applications which are specially designed to run
on network are known as ‘Distributed
applications’.
The technology of creating and running an
application in parts is also called ‘application
partitioning’.
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CST Applications
A distributed application consists of a server
portion where most of the processing and storage
is performed.
This server portion is always executed and stored
on the server
This is also known as the ‘Back-End’.
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CST Applications
The part of the application that runs on the client
and which provides the interface to the client is
known as the ‘front-end’
The front-end through its interface provides many
functionalities to the client.
The client can performs many important tasks
using this interface.
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CST Applications
In the CST model, an application is split into a
front- end client component and a back-end
server component.
The front-end part of the application runs on a
workstation and receives data that is input by the
user.
The client’s front-end prepares the data for the
server by preprocessing it in some fashion.
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CST Applications
This processed information is then sent to the
server.
The data is sent to the server in form of some request.
The back-end server component receives the
client’s request and processes it and returns
information to the client.
The client receives the information and presents it
to the user
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CST Applications
A good example of CST application is a web
application that is designed for Internet
Information Services(IIS).
Such applications are prepared by using
ASP(Active server pages) programming and client
side scripting.
The ASP program runs on the server and the client
side scripting runs on the client.
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CST Applications
Basically a CST application has three main
components:
The front-end application
The back-end application
Network operating system
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The Front-End & Back-End
In its general meaning, the term ‘Front-End’ refers
to the initial and the end stages of process flow.
These terms acquire more special meanings in particular areas
The general idea is that the front-end is
responsible for collecting input from user.
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The Front-End & Back-End
The input can be in a variety of formats but is
processed in such a way that it conforms to a
specification that the back-end can use.
The connection of the front-end to the back-end
is through the interface
In a s/w design, the front-end is the part of s/w
system that interacts directly with the user.
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Front-End
Back-End
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The Front-End & Back-End
The back-end is the part which contains
components that processes the output for the
front- end.
The separation of the ‘front-end’ and ‘back-end’
is a kind of abstraction.
Abstraction helps to keep different parts of the
system separated
There are many example of front-end and the
back-end which are used in computer field.
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The Front-End & Back-End
Front-end is the part or the interface that helps a
user to interact with the machine.
For example:- Windows explorer can by defined as the front-end to the computer file system.
Similarly the GUI interface on the machines can
be defined as the front-end of the machine.
Most of the s/w packages have a front-end with
which user interacts and operates the s/w.
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The Front-End & Back-End
In complies the front-end translates a computer
programming source language into an
intermediate representation
And the back-end works with the internal
representation to produce code in a computer
language
The back-end usually produces machine
language code that runs faster
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The Front-End & Back-End
Similarly when we create s/w using dot net, dot
net works as the front-end.
Whereas the database where the data is stored Example:- SQL or Oracle is called the back-end.
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Network Software
In order to define ‘Network s/w’ one must define
the individual terms ‘Network’ and ‘s/w’
A network is made up of two or more computers that are linked together.
Networks can be used for a variety of purposes
Generally networks are used to send information
from one computer to another computer.
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Network Software
They are also used to play games or talk to a
friend or to combine computing power.
S/w can be defined as a program or a set of programs written to perform specific tasks.
So, using the definitions of network and software
we can define network s/w as follows:
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Network Software
Network s/w makes it possible for computers to
communicate or connect to one another.
It can also be defined as the s/w which helps to send information from one computer to another.
The network s/w contains information about how
data is to be sent in packets to another
computer.
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Network Software
Packet information includes the ‘header’ and the
‘trailer’
The header and the trailer contains information for the computer to which the information is being
sent.
This information includes address of the computer
to which the packet is sent, and how the
information is coded etc.
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Network Software
Information is transferred b/w computers as either
electrical signals in wires, as light signal in fiber
optical cable or as electromagnetic waves.
Thus network s/w is the s/w which helps computers
in a network to communicate with each other.
They are also responsible for sending/exchanging
information b/w two computers
Some network s/w are Windows Server2003, Linux,
Window Server 2000, Novell Network etc.
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Role of serverUNIT III
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On the basis of Usage
1. FILE SERVER
2. COMPUTER SERVER
3. DATA SERVER
4. COMMUNICATION SERVER
5. APPLICATION SERVER
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1.
Manages workgroups applications & Data Files
Shared by the group and among the groups
File Servers are I/O oriented
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1.
Large amount of data Storage and data transfer
Space for storage is allocated and free space is managed by
the file server
Whenever data from a file is requested, a file server transmits
all records of a file and the entire index to the client
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1.
Requires many slots for network connection
It also needs a large storage capacity and fast
hard disk sub-system.
The main work of file server is to manage,
maintain and serve the file whenever a file is
requested.
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2. Compute Server
Compute Server is used in a 3 Tier Architecture
Processing Server
CS passes client requests to a data server
Forwards the result
Processing on the client request.
Processing authenticity for security.
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3. The Data Server
Data storage and management.
Conjunction of one or more computer servers
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3. The Data Server
Processing is done by rule based procedures
Data validation, requires data management
function.
Multiple searches of data and frequent updates
of massive tables.
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3. The Data Server
Task require fast processors
Large amount of memory and substantial hard
disk capacity.
Servers send relatively small amount of data
across the network.
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4. The Communication
Server Communication Servers provide gateways to LAN’s, Network
System requirements with perhaps the greatest demands
being those for multiple slots and fast processors.
Powerful h/w to translate networking protocols.
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5. Application Server
Application server is a machine that Server as a
host
Applications are downsized from a host, oneoption is to install the application on a smaller
machine that runs the same s/w & to hook all the
users to the new box
Process Requires no modifications to the based
app s/w
Host is server to GUI based clients
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On the basics of SizeMICRO SERVER
SUPER SERVER
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Micro Server :-
Performs all the functions which a Server needs
Micro Servers used the Intel 486 Chips to run at 33Mhz or
higher with 16 MB RAM.
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Micro Server
Multiprocessing provided by certain O.S do not
provide multiprocessing
Example:- Novell’s Netware does not provide multitasking
Micro Servers use Intel 3.06GHz or Xeon or higher
processing speed chips with 1 to 4 GB RAM
OS support Symmetric multiprocessing
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Micro Server
Latest Servers use Dual Core Technology having
64 Bit processing capabilities
Tremendous processing and executing powers
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2. Super Server
Super Server is specifically designed for the CST
Provides certain hardware features
Multiple processors, large amounts of memory
High speed disk arrays
Specialized applications are used
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Super Server
Higher configuration h/w & s/w
Advantage over a Micro Server
Increased Processing Power : multiple processors
Increased I/O capabilities :
Increased disk capacity :
Improved Memory Management :
Improved reliability :
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Super Server
Improved maintainability :
Eg : Param (Pune, India)
ANURAG (India)
CLAY 1, CLAY 2 and CLAY 3, CRAY.
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Features of Server
Server plays a very important role in the network
Speed and the Performance of a network
Server machine is a powerful machine
The general features possessed by a server are as follows :
Multi Processing
Multi Threading
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Features
Disk Arrays
Disk Mirroring
Disk Duplexing
Parity Checking
RAID Components
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1. Multi Processing
Multiple processors to increase processing speed
Workload is shared by the processors
Multiple processing can be further classified
1. Symmetric Multiprocessing
Dynamically assigned to any processor
Processing speed and resources are maximized
Capability supported by the Network Operating System(NOS) or
Server Operating System (SOS)
Application s/w should also support multiprocessing
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Network
Services
File Systems
DBMS
Engine
Disk I/O
Processo
r Processor
Processo
r
Processor
Symmetric
Multiprocessing
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1. Multi Processing
2. Functional Multi Processing
Assigns a set of tasks to a processor
Multi processing also supports multi threading
Concurrent execution of multiple tasks
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Network
Services
File
SystemPrint Disk I/O
Network
Services
Processo
r
File
Systems
Processor
Process
or
Disk I/O
Processo
r
Functional Multiprocessing
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2. Multi Threading
Thread is smallest unit of execution
System can schedule it to run
A path of execution through a process
Thread consists of stack, an instruction pointer, a
priority, the CPU state and an entry in the system’s
scheduler list.
Thread may be blocked, scheduled to execute or
running.
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2. Multi Threading
Thread communicate by sending messages to
each other and they compete for ownership of
various semaphores
The allocation of computing resources between
the individual threads
Thread asks the system for an instruction to carry
out.
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2. Multi Threading
If no instruction is ready, the thread is suspended
until it has something to do
If the instruction is ready, the thread performs the task and makes another request to the system for
work
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3. Disk Array
Fault tolerant disk arrays, Redundant Array of
Inexpensive Disks(RAID)
Such Disks are standard on super servers
Disk Array’s usually include a file server and
software that controls access to the individual
drives.
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2
RAID Redundant Array of Inexpensive Disks
14
3
RAID
Multiple drivers are treated as a single logical
drive by the server operating system
Transparently recover from the failure
The data is actually broken into chunks and
simultaneously written to multiple disks
14
4
RAID
If a disk fails, the data can be reconstructed by
reviewing the places of data
RAID currently has five levels of data protectionand error correction
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5
1. Disk Mirroring
Disk Mirroring is the process of creating a mirror
duplicate of a disk
Such facilities are usually provided by the SOS
In this system two disks are attached to the same
disk controller
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6
2. Disk Duplexing
Creating duplicate disk.
Individual controllers are provided for each disk
One of the disk is duplicated
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7
3. Parity Checking
An extra bit is added to ensure that the
information is transmitted accurately
The extra added bit is called the ‘Parity Bit’
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8
4. Redundant
Components
Redundant Server Components such as disk
driver. Power supplier an automatic supplier and
automatic recovery features are option on serversand standard on super servers.
Some super servers offer mirrored processors and
include remote alarms that immediately warn of
network trouble.
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9
Network Operating
SystemNOVELL NETWARE
LAN MANAGER
15
0
Network Operating
System
Server Operating System is NOS
Operating system which is aware of a network
Additional features than a normal operating
system
15
1
Network Operating
System
These features include:
File and Printer Sharing
Data Security and Authentication
Distributed Applications
Messaging
Centralized Administration
15
2
Network Operating
System
Its main task is to receive and respond to user
requests for services
A NOS manages the services of a server
Various Network management tools
Run many other software
Generally an operating system manages the
resources of the server
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3
Network Operating
System
Software to communicate with other computer
via a network
Manages multiple requests concurrently
Self contained operating system
15
4
Network Operating
System
For example:- Windows NT, UNIX
Remote drives on the server can be accessed
The server to handle requests from the client to
share file and applications as well as network
devices
15
5
Network Operating
System LAN’s which can either be peer to peer networks or CST
based.
Example:- NOS include Windows NT, Novell Netware and
Banyan VINES.
Cisco’s Internet Work Operating System (IOS) can be used as
OS on router
15
6
Network Operating
System
Peer-to-peer network, the NOS allows each
station to be Client & Server
Non peer to peer network, dedicated servers areused
File and print services a network OS include
directory services.
Messaging service as well as network
management and multi protocol routing
capabilities.
15
7
Network Operating System
NOS can be used for a variety of purposes.
The basic functions of a NOS are:
Authenticate user access
Share files and printers and exchange messages.
15
8
Network Operating
System
Centralizing administration of multiple computers
from a single management console.
Distributed applications that share processing onmultiple computers.
15
9
Network Operating
System
Some of the popular NOS are:
Microsoft Windows 2000/2003/2008/2012.
Novell NetWare
Various flavours of UNIX
LINUX
Mac OS etc..
16
0
1. Novell NetWare
Novell that support DOS, Windows, OS/2 and
Macintosh clients
Network Operating System
Supports file and printer sharing, email, remote
access, inter LAN communication via a bridge or
a gateway
16
1
1. Novell NetWare
Controlling system resources and their uses.
Different versions
Version depends on type of services
16
2
Novell NetWare
The different versions of Novell Netware are :
Novell NetWare Lite
Novell NetWare 2.2
Novell NetWare 3.11
Novell NetWare 4.0
With each new version of Novell NetWare some
new additional features were added to it.
16
3
Novell NetWare
Some of the features include:
Increased number of clients can be connected
the server.
Better memory management.
Support for latest processor.
Support for increased RAM.
Support for Multiple protocols.
16
4
Novell NetWare
Better security options (Example:- Disk Mirroring,
disk duplexing or redundant components)
NetWare is used by organization, large and small
Provides common services
16
5
LAN Manager
Developed by IBM
LAN manager is NOS for networking
Different network OS according to characteristics
Requires that the server run OS/2
Clients use Macintosh or any OS
Works across multiple protocol
16
6
LAN Manager
Basic Features provided are:
Concept of Domain Name System.
Support for Multiprocessing.
Remote access service
Latest features a Server needs
16
7
Server Operating System
LINUX
OS/2
16
8
Linux
Introduction
Supports a large number of hardware
Provides multiuser multitasking OSE(Operating
System Environment)
Freely used on WS(Web Server), DNS(Domain
Name System), File Server(FS) etc…
Server side Application:
Apache Web Server
Samba Server
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9
Samba enable a Linux Server to provide file and
print services to other platforms such as Windows
and Apple Macintosh.
17
0
OS/2
OS/2 server platform, intel’s product
Provided by IBM in SAA(System Application
Architecture) model
Multitasking services
Network Operating System directly supported with
OS/2 are LAN Manager and LAN Server.
Combination of Novell with OS/2 DataBase And
Applications Server.
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1
System Application
Architecture
SAA is IBM’s distributed environment
SAA define standards for CUA(Common User
Access), CPI(Common Programming Interfaces), Common Communication Link.
SAA framework is AD/Cycle
AD/Cycle designed to use third party tools
17
2
17
3
client server
ArchitectureUNIT IV
17
4
Concept & Components
of C/S
C/S architecture is based on framework
Consists of many PC’s, workstations & small
mainframe machines
Connected with communication media or
channel.
17
5
Tiered Architecture
Generally there are two types of nodes in a network.
One is Client and another is Server.
Two Tiered Architecture “the Client and the Server”.
Directly sends a response to the CS.
Direct communication between CS.
17
6
Main types of DBMS architecture:
1. Two tier Architecture
2. Three tier Architecture
17
7
Two Tiered Architecture
In a two tiered architecture there is no third party [machine ]
involved.
The server
2 Tiered Architecture
Client
17
8
Advantages of 2 Tier
Architecture
Easy to update data
Easy to upgrade and maintain such networks
17
9
Disadvantages of 2 tier
Architecture
Traffic jams in networking
Large number of clients sends requests and this
causes troubles for the server
More Clients more trouble
Server goes down and the Clients requests
cannot be fulfilled
18
0
Three Tiered Architecture
Networks consists of three different kinds of nodes:
Client : which requests data
Server : which processes data
Database Server : which stores data.
Such an architecture is called ‘ Three Tiered
Architecture’.
18
1
Clien
t
The
Server
The
Server
3 Tiered Architecture
18
2
Advantages of 3 Tier
Architecture
3-tier architecture one Server free to only
processing.
Server stores all the data only and does no needto do any processing.
Load/Burden is reduced on the Server.
Servers perform much better
18
3
Advantages of 3 Tier
Architecture
Better security control on data.
A Hacker has to pass through the processing
server to reach to the database
18
4
Disadvantages of 3 Tier
Architecture
Load on the network
Difficult to run or test a software
18
5
Communication Between
C/S
18
6
Client requests to the server for data or
information
Server is the machine which serves the data orinformation.
ORB are the middleware that enable Client &
Server programs to establish session with each
other
Client & Server can communicate, independent
of their location on the network or programming
interface
18
7
Process of Client invoking or call to an Application
Programming Interface(API)
Client issues the call, which is intercepted by the ORB
ORB takes call & is responsible for locating a server object
that is able to implement the request
ORB communicate among themselves using the General
Inter-ORB Protocol (GIOP) or Internet Inter-ORB Protocol(IIOP)
Any ORB can fulfil any Client request on the network
18
8
Use of API
Application Programming Interface let C and Assembly
language interact with services and programming tools
Window OS provides API to access standard operating system
and networking services and functions
Window OS provide predefined sets of API for various
purposes:-
(Telephony)TAPI for accessing voice, data of fax
(Messaging)MAPI for messaging functions
API call to the computer browser service
18
9
Middleware technology in
CSC
Three tier architecture
Intermediate layer between the client and
database server
19
0
Open System
Interconnection(OSI)
Intro:
OSI was developed by ISO(International
Organization for Standardization)
Model for universally accepted networking
protocols
Model describes how information moves
Conceptual model composed of 7 layers
19
1
Upper
Layer of
software
layer
Heart
of OSI
Lower
Layer of
hardware
layer
7
6
5
4
3
2
1
19
2
OSI Reference Model: 7 Layers
OSI Model19
3
1. Physical Layer
First layer of OSI model
‘Nut & Bolts’ layer
Physical interface b/w devices
Physical and electrical connection
Transmission media
Different protocols
19
4
2. Data Link Layer
2nd layer of the OSI model
Converts frames of data
Responsible:
Framing, Flow control, Error free Communication
Bridges and NIC work on this layer
Ensures that the data is transferred reliably
Responsible for addressing, Frame sequencing, error
detection and recovery
19
5
Data Link Layer
Layer deals with getting data packets on and off
the wire
Error Detection, Correction and Retransmission
Layer is divided into two layers
LLC – Logical Link Control
MAC – Media Access Control
19
6
Frame
PacketData
Trailer
Data
Header
CRC(Cyclic Redundancy
Check)
Source MAC Address
Destination MAC
Address
A cyclic redundancy check (CRC) is an error-detecting
code commonly used in digital networks and storage devices to
detect accidental changes to raw data.
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7
3. Network Layer
Addressing and routing of packets
Establishing and releasing connections
Transferring data, Generating and confirming
receipts and resetting connections
Packets sent from one device to another
Routing and flow control are formed here
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8
Packets
SegmentNetwork
Header
Source IP Address
Destination IP Address
19
9
4. Transport Layer
The Heart of the OSI model
Responsible for providing reliable transport services to Upper
Layer
Flow control
Multiplexing for combining data from several sources
Layer uses TCP/IP protocol
Port is a Logical Communication Channel
20
0
Segment
DataTransport
Header
Source Port No
Destination Port
No
Protocol No
Sequence No
It provides data
delivery
mechanism b/w
the application in
the network
20
1
Hello
!
Ho
wAR
E
Yo
u?
20
2
sequencing
Hello
!
1/5
Ho
w
2/5
AR
E
3/5
Yo
u
4/5
?
5/5
20
3
5. Session Layer
Responsible for:
Establishing and Terminating a session in a network
Synchronizing data exchange b/w 2 computers
NetBIOS protocol works at this layer
Sessions ID’s
Examples:
RPC – Remote Procedural Call
SQL – Structured Query Language
ASP – AppleTalk Session Protocol
20
4
6. Presentation Layer
Presentation layer is responsible for
1 Data Translation
2 Data Compression
3 Data Encryption.
Interpretation of graphics
commands
E.g.: ASCII, MIDI, WAV, MP3 etc.
20
5
6.1. Data Translation
Application layer will need to convert data
Receiving format understood and accepted
OSI model to ensure smooth file transfer
Data formats include postscript, American Standard Code for
Information Interchange (ASCII), or BINARY such as Extended Binary Coded Decimal Interchange Code (EBCDIC)
20
6
6.2. Data Compress
The goal of data compression is to represent an
information source (a data file, an image) as
accurately as possible using the fewest number of bits
For example, 25.888888888
This string can be compressed as:
25.[9]8
Interpreted as, "twenty five point 9 eights", the
original string is perfectly recreated, just written in
a smaller form
20
7
6.3. Data Encryption.
Process of transforming information (plaintext)
Using an algorithm (called cipher) to make it
unreadable to anyone except those possessing special knowledge
Usually referred to as a key.
Result of the process is encrypted information
(referred to as cipher text).
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8
7. Application layer
Window b/w user and other
networking services
Runs the s/w with which the user
interacts
FTP and HTTP protocols are used
Layer acts as an interface b/w user
and network
20
9
7. Application layer Protocols
HTTP – Hyper Text Transfer Protocol
FTP – File Transfer Protocol
POP – Post Office Protocol
SMTP – Simple Mail Transfer Protocol
SSL – Secure Socket Layer
Telnet – for remote computer access
21
0
21
1
IPC (Inter Process
Communication)
Allows one process to communicate with another
process
Processes run on same computer or on different computers which are connected through a
network
IPC techniques are divided into methods
Message passing, Synchronization, shared
memory and Remote Procedure Calls(RPC)
21
2
Client Server Computing written by Munesh Trivedi
Or Mamta Rani
The Essential Client/Server survival Guide written
by Robert Orfali , Dan Harkey Or Jeri Edwards
21
3
Unit V
C/s system
development
21
4
Network Management
Network means connecting two or more
computers in such a way that they are able to
share data & h/w
Networks can by very small or very large
Every type of network faces problems regularly
Problems need to be solved regularly for easy &
good performance of the network
21
5
Network Management
Network can face the following problems:-
1. No connection
2. Wrong or no user accounts
3. Faulty or loose wires
4. Domain name problems
5. Server down
6. H/w problems (switch, router)
21
6
Network Management
7. No services available
8. Wrong or invalid permissions
9. Server OS problems
Network has to be managed regularly
“Network Administrator”
21
7
Five key OSI management areas
Fault management
Performance management
Inventory management
Accounting management
Configuration management
Security management
21
8
Remote System
Administrator
Able to create very large network
C/S machine very far form each other
Access files or folders
Install or uninstall any s/w, format, restart
Save time & money
Facility provided by the OS
21
9
Remote System
Administrator
Remote administrator can also be very
dangerous
Unauthorized user can easily Access
Hacking
Difficult to catch such user
22
0
LAN Management
LAN
Limited area
in a campus
Regular problems
Management is also compulsory
Same Network management
22
1
The responsibility of network administrator or LAN
administrator that the entire network will not be
crashed or failed.
The data or information will never be lost on any
cost
22
2
LAN network management there are certain issues or services
Network Maintenance
Network Integration
Capacity Planning
Equipment Maintenance
Security Administration
Network Cabling & Installation
Network Application & Administration
Server & PC Data Backup
22
3
1. Network Maintenance
The computer are connected with each other
The structure & layers what type of connections
are used for better network
We can use routers at some places, hubs,
switches
Facilities of disk mirroring, disk duplexing
There is less possibility of network failures
We can maintain the network & make it work
efficiently & effectively
22
4
2. Network Integration
Network Integrity mean that all the systems should
work & function Homogenously
System should have a contact with the Server
22
5
Developing Application
On RDBMS
RDBMS
S/w used to store large amount of data
Processes data & provide information to user
Technical users use SQL & RDBMS
GUI
22
6
Developing Application
On RDBMS
Designed in s/w like VB6 or VB.net
Screen fully graphical, friendly & easy to use
Screens acts as “FRONT-END”
RDBMS acts as “BACK-END”
Used in Banks, Railways, govt. offices etc…
22
7
GUI Design Concepts
GUI
Gives controls to work in GUI
Help to work easily & fast
Controls include textbox, radio button etc…
Important role in designing graphical screens
22
8
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9