1. Client Server Technology

2. UNIT -1

5. 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

6. Definition
 Client Server Computing (CSC) is that Server Operating
System (OS) accepts requests for data from Client Operating
System & returns the results(services) to the Client.
 Client manipulates or calculates data and presents the results
to the user.

7. 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

8.  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

9. 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

10. University Of Los
Angeles

11. 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.

12. 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

13. 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

14. Evolution of Client
Server Concept

15. Evolution
 Evolution [growth] of networking
 Various reasons can be broadly categorized into following:
1. Hardware Trends
2. Software Trends.
3. Networking Trends.

16. Hardware Trends
 Hardware Trends can further be divided into the
following:
-Power/Speed
-Chips [Micro Processor]
-Memory
-Storage Devices

17. -Power/ Speed

18. -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..

19. -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

20. -Memory

21. Memory
Hard Disk Drive
(H.D.D)

22. RAM for different Processors
 Extended
Data Output
(EDO)
 Static
Dynamic (SD)
 Dual Data
Rate(DDR)
 DDR3

23. 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

24. 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

25. Software Trends
1. Graphical User Interface (GUI) Concept.
2. RDBMS.
3. Multi Threading Processing.

26. 1. GUI concept
 GUI is Graphical User Interface.
 WYSWYG [What You See is What You Get].

27. 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.

28. 2.RDBMS

29. 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.

30. 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

31. 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)

32. Advantages of
CST computing/
need & motivation
for C/S Approach

33. Advantages
 Networking plays a very important role.
 It is life line of today’s modern offices.
 LAN to intranet to internet.

34. Advantages
 Connectivity.
 Sharing Devices.
 Flexibility and Scalability.
 Centralized Control.
 Faster Delivery of Systems.
 Resource Utilization.
 Reduction in Network Traffic.

35. 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.

36. Advantages -
Connectivity
 ‘File Sharing’
 ‘Resource Sharing’
 ‘Remote Accessing’.

37. Advantages -Connectivity
 Accessing a Remote Computer through Network
 All these facilities are provided by the ‘Network
OS’ or the ‘Server OS’.

38. Advantages -Sharing
Devices In CST we share various devices
 Sharing of resources is done through networking

39. 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.

40. Advantages -Flexibility
and Scalability
 Add or remove Computers
 Data access through networking is easy

41. Advantages -Centralized
Control
 Centralized facility is the one in which data is
transmitted through channel.
 In past centralized facility was difficult to
implement and maintain.
 Client Server Technology (CST) allows facilities to
combine Centralized and Decentralized
Architectures.

42. 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.

43. Advantages -Centralized
Control Server maintains an Intelligent Database with rules and
security
 E.g.: Backup and Recovery procedures are centralized

44. 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.

45. 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

46. 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.

47. Client Server
Environments

48. 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.

49. 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

51. 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

52. Characterization
of Client/Server
Computing
COMPONENTS OF CLIENT SERVER TECHNOLOGY
/ COMPUTING

53. Components
 There are mainly three components.
1. The Client
2. The Server
3. The Network

54. 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

55. The Server
 Server machine is designed for server
functionality
 Comparison to desktop machine
 Increased Memory capabilities
 Increased Storage capabilities

56. The Server
 Increased processing power [ through multi
processor technology].
 Improved Reliability with built in reliability features
such as:
-Uninterruptible Power Supply
-Fault Tolerance
-Disk Mirroring

57. The Server
 Evaluating server h/w:-
1. Reliability
2. Availability
3. Flexibility

58. 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

59. 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.

60. 2. Availability
 Availability refers?
 Systems have self healing routines
 Fault tolerant alarms
 Specific configuration rebooted from a remote
site

61. 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

62. 3. The Network
 Network connecting devices
 Managed and maintained by network
 Managed I/O processes

63. 2. Distributed Working
 Distributed computing is a method of computer
processing

64. The Role of
Client
UNIT II

65. The Client
 Request to Server
 Network Operating System(NOS) Software who
helps in making the request and forwarding the
request to the server
 NOS software translates or adds the specifics
required
 IPC (Inter Process Communication).

66. 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

67. 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.

68. 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.

69. 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.

70. 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.

71. 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

72. 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.

73. 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

74. 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.

75. 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’

76. 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.

77. 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

78. 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

79. 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)

80. 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

81. 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

82. 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

83. 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

84. 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

85. 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.

86. 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

87. 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.

88. 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

89. 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

90. 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.

91. 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

92. 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.

93. CST Application

94. 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’.

95. 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’.

96. 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.

97. 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.

98. 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

99. 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.

100. CST Applications
 Basically a CST application has three main
components:
 The front-end application
 The back-end application
 Network operating system

101. 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.

102. 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.

103. Front-End
Back-End

104. 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.

106. 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.

107. 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

109. 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.

110. 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.

111. 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:

112. 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.

113. 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.

114. 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.

115. Role of server
UNIT III

116. On the basis of Usage
1. FILE SERVER
2. COMPUTER SERVER
3. DATA SERVER
4. COMMUNICATION SERVER
5. APPLICATION SERVER

117. 1.
 Manages workgroups applications & Data Files
 Shared by the group and among the groups
 File Servers are I/O oriented

118. 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

119. 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.

120. 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.

121. 3. The Data Server
 Data storage and management.
 Conjunction of one or more computer servers

122. 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.

123. 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.

124. 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.

125. 5. Application Server
 Application server is a machine that Server as a
host
 Applications are downsized from a host, one
option 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

126. On the basics of Size
MICRO SERVER
SUPER SERVER

127. 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.

128. Micro Server
 Multiprocessing provided by certain O.S do not
provide multiprocessing
 Example:- Novell’s Netware does not provide multi
tasking
 Micro Servers use Intel 3.06GHz or Xeon or higher
processing speed chips with 1 to 4 GB RAM
 OS support Symmetric multiprocessing

129. Micro Server
 Latest Servers use Dual Core Technology having
64 Bit processing capabilities
 Tremendous processing and executing powers

130. 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

131. 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 :

132. Super Server
 Improved maintainability :
 Eg : Param (Pune, India)
 ANURAG (India)
 CLAY 1, CLAY 2 and CLAY 3, CRAY.

133. 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

134. Features
 Disk Arrays
 Disk Mirroring
 Disk Duplexing
 Parity Checking
 RAID Components

135. 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

136. Network
Services
File Systems
DBMS
Engine
Print
Disk I/O
Processo
r Processor
Processo
r
Processor
Symmetric
Multiprocessing

137. 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

138. Network
Services
File
System
Print Disk I/O
Network
Services
Processo
r
File
Systems
Processor
Print
Process
or
Disk I/O
Processo
r
Functional Multiprocessing

139. 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.

140. 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.

141. 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

142. 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.

143. RAID Redundant Array of Inexpensive Disk

144. 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

145. RAID
 If a disk fails, the data can be reconstructed by
reviewing the places of data
 RAID currently has five levels of data protection
and error correction

146. 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

147. 2. Disk Duplexing
 Creating duplicate disk.
 Individual controllers are provided for each disk
 One of the disk is duplicated

148. 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’

149. 4. Redundant
Components
 Redundant Server Components such as disk
driver. Power supplier an automatic supplier and
automatic recovery features are option on servers
and standard on super servers.
 Some super servers offer mirrored processors and
include remote alarms that immediately warn of
network trouble.

150. Network Operating
System
NOVELL NETWARE
LAN MANAGER

151. Network Operating
System
 Server Operating System is NOS
 Operating system which is aware of a network
 Additional features than a normal operating
system

152. Network Operating
System
These features include:
 File and Printer Sharing
 Data Security and Authentication
 Distributed Applications
 Messaging
 Centralized Administration

153. 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

154. Network Operating
System
 Software to communicate with other computer
via a network
 Manages multiple requests concurrently
 Self contained operating system

155. 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

156. 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

157. Network Operating
System
 Peer-to-peer network, the NOS allows each
station to be Client & Server
 Non peer to peer network, dedicated servers are
used
 File and print services a network OS include
directory services.
 Messaging service as well as network
management and multi protocol routing
capabilities.

158. 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.

159. Network Operating
System
 Centralizing administration of multiple computers
from a single management console.
 Distributed applications that share processing on
multiple computers.

160. 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..

161. 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

162. 1. Novell NetWare
 Controlling system resources and their uses.
Different versions
 Version depends on type of services

163. 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.

164. 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.

165. Novell NetWare
 Better security options (Example:- Disk Mirroring,
disk duplexing or redundant components)
 NetWare is used by organization, large and small
 Provides common services

166. 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

167. LAN Manager
 Basic Features provided are:
 Concept of Domain Name System.
 Support for Multiprocessing.
 Remote access service
 Latest features a Server needs

168. Server Operating System
LINUX
OS/2

169. 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

170.  Samba enable a Linux Server to provide file and
print services to other platforms such as Windows
and Apple Macintosh.

171. 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.

172. 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

174. client server
Architecture
UNIT IV

175. 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.

176. 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.

177. Main types of DBMS architecture:
1. Two tier Architecture
2. Three tier Architecture

178. Two Tiered Architecture
 In a two tiered architecture there is no third party [machine ]
involved.
The server
2 Tiered Architecture
Client

179. Advantages of 2 Tier
Architecture
 Easy to update data
 Easy to upgrade and maintain such networks

180. 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

181. 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’.

182. Clien
t
The
Google
Server
The
Facebook
Server
3 Tiered Architecture

183. Advantages of 3 Tier
Architecture
 3-tier architecture one Server free to only
processing.
 Server stores all the data only and does no need
to do any processing.
 Load/Burden is reduced on the Server.
 Servers perform much better

184. Advantages of 3 Tier
Architecture
 Better security control on data.
 A Hacker has to pass through the processing
server to reach to the database

185. Disadvantages of 3 Tier
Architecture
 Load on the network
 Difficult to run or test a software

186. Communication Between
C/S

187.  Client requests to the server for data or
information
 Server is the machine which serves the data or
information.
 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

188.  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

189. 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

190. Middleware technology in
CSC
 Three tier architecture
 Intermediate layer between the client and
database server

191. 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

192. Upper
Layer of
software
layer
Heart
of OSI
Lower
Layer of
hardware
layer
7
6
5
4
3
2
1

193. OSI Reference Model: 7 Layers
OSI Model

194. 1. Physical Layer
 First layer of OSI model
 ‘Nut & Bolts’ layer
 Physical interface b/w devices
 Physical and electrical connection
 Transmission media
 Different protocols

195. 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

196. 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

197. Frame
Packet
Data
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.

198. 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

199. Packets
Segment
Network
Header
Source IP Address
Destination IP Address

200. 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

201. Segment
Data
Transport
Header
Source Port No
Destination Port
No
Protocol No
Sequence No
It provides data
delivery
mechanism b/w
the application in
the network

202. Hello
!
Ho
w
AR
E
Yo
u
?

203. sequencing
Hello
!
1/5
Ho
w
2/5
AR
E
3/5
Yo
u
4/5
?
5/5

204. 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

205. 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.

206. 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)

207. 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

208. 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).

209. 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

210. 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

212. 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)

213.  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

214. Unit V
C/s system
development

215. 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

216. 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)

217. Network Management
7. No services available
8. Wrong or invalid permissions
9. Server OS problems
 Network has to be managed regularly
 “Network Administrator”

218.  Five key OSI management areas
 Fault management
 Performance management
 Inventory management
 Accounting management
 Configuration management
 Security management

219. 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

220. Remote System
Administrator
 Remote administrator can also be very
dangerous
 Unauthorized user can easily Access
 Hacking
 Difficult to catch such user

221. LAN Management
 LAN
 Limited area
 in a campus
 Regular problems
 Management is also compulsory
 Same Network management

222.  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

223.  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

224. 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

225. 2. Network Integration
 Network Integrity mean that all the systems should
work & function Homogenously
 System should have a contact with the Server

226. 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

227. 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…

228. 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