2. Contents
Overview
History
Introduction
Working of Distributed System
Type
Motivation
Goals
Characteristics
Architecture
Security and Standards Challenges
Example
Advantages
Disadvantages
Conclusion
Reference
3. Overview of Distributed Computing
• Distributed Computing is a field of computer science that
studies distributed systems.
• A Distributed System is One in Which H/W & S/W
Components Located at Networked Computers Communicate
their Actions Only By Message Passing
• In The Term Distributed Computing The Word Distributed
Means Spread out across space. Thus, Distributed Computing
is an activity performed on a distributed system.
• These Networked Computers may be in the same city, same
country i.e. in same world.
4. History
• The use of concurrent processes that communicate by
message-passing has its roots in operating system
architectures studied in the 1960s
• The study of distributed computing became its own
branch of computer science in the late 1970s and
early 1980s.
• The first conference in the field, Symposium on
Principles of Distributed Computing (PODC), dates
back to 1982, and its European
counterpart International Symposium on Distributed
Computing (DISC) was first held in 1985.
6. Introduction
• The word distributed in terms such as “ distributed
system", "distributed programming", and " distributed
algorithm " originally referred to computer networks
where individual computers were physically
distributed within some geographical area.
• The terms are nowadays used in a much wider sense,
even referring to autonomous processes that run on
the same physical computer and interact with each
other by message passing.
7. Working of Distributed System
• A distributed computing architecture consists of very
lightweight software agents installed on a number of
client systems, and one or more dedicated distributed
computing management servers.
• There may also be requesting clients with software
that allows them to submit jobs along with lists of
their required resources.
10. Types of Distributed System
Distributed Computing System
• Grid Computing
• Cluster Computing
• Cloud Computing
Distributed Information System
Distributed Pervasive System
11. Distributed Computing System
Grid Computing :-
Grid computing is the collection of computer resources
from multiple locations to reach a common goal. Grid
computing is a processor architecture that combines
computer resources from various domains to reach a
main objective. In grid computing, the computers on the
network can work on a task together, thus functioning as
a supercomputer.
12.
13. • Cluster Computing :-
A computer cluster is a single logical unit consisting of
multiple computers that are linked through a LAN. The
networked computers essentially act as a single, much
more powerful machine. A computer cluster provides
much faster processing speed, larger storage capacity,
better data integrity, superior reliability and wider
availability of resources.
Computer clusters are, however, much more costly to
implement and maintain. This results in much higher
running overhead compared to a single computer.
14.
15. • Cloud Computing :-
Cloud computing is a type of computing that relies
on sharing computing resources rather than having local
servers or personal devices to handle applications.
In cloud computing, the word cloud (also phrased as "the
cloud") is used as a metaphor for "the Internet," so the
phrase cloud computing means "a type of Internet-based
computing," where different services — such as servers,
storage and applications — are delivered to an
organization's computers and devices through the Internet.
16.
17. Distributed Information System :-
Goal :- Distributed Information System across several
servers
Remote processes called Clients access the servers to
manipulate the information.
Different communication models are used.
The most usual are RPC (Remote Procedure Calls) and
the object oriented RMI (Remote Method Invocations)
often associated with Transaction systems Examples:
o Banks
o Travel Agencies
o Rent-a-Cars………Etc……
18. Distributed Pervasive System
These are the distributed system involving mobile and
embedded computer devices like small, wireless, battery-
powered devices(PDA’s, smart phone….etc.)
These system characterized by their “instability” when
compared to more “traditional” distributed systems
pervasive system are all around us, and ideally should be
able to adapt to the lack of human administrative control:
• Automatically connect to a different n/w;
• Discover services and react accordingly;
• Automatic self configuration (e.g.: UPnP-Universal
Plug and Play)…..
Examples …. Home system, electronic Health care
system, sensor networks, ……
19. Motivation
The main motivation in Distributed System are the
following ……….
o Inherently distributed application.
o Performance/Cost.
o Resource Sharing.
o Flexibility and Extensibility.
o Availability and Fault Tolerance.
o Scalability
20. Goals
• Making Resources Accessible:
The main goal od DS is to make it easy for the users and application to
access remote resources, and to share then in a controlled and efficient
way.
• Distribution Transparency:
An important goal of DS is to hide the fact that its processes and
resources are physically across multiple computers.
• Openness:
An open DS is a system that offers services according to standard
rules that describe the syntax and semantics of those services.
• Scalability
scalability of a system can be measured along at least
three different dimensions.
23. Client–server
Architectures where smart clients contact the server for data
then format and display it to the users. Input at the client is
committed back to the server when it represents a permanent
change.
Three-tier
Architectures that move the client intelligence to a middle tier
so that stateless clients can be used. This simplifies application
deployment. Most web applications are three-tier.
N-tier
Architectures that refer typically to web applications which
further forward their requests to other enterprise services. This
type of application is the one most responsible for the success
of application servers.
Peer-to-peer
Architectures where there are no special machines that provide
a service or manage the network resources. Instead all
responsibilities are uniformly divided among all machines,
known as peers. Peers can serve both as clients and as servers
24. Security and Standards Challenges
• The major challenges come with increasing scale. As
soon as you move outside of a corporate firewall,
security and standardization challenges become quite
significant.
• Most of today's vendors currently specialize in
applications that stop at the corporate firewall, though
Avail, in particular, is staking out the global grid
territory.
• Beyond spanning firewalls with a single platform, lies
the challenge of spanning multiple firewalls and
platforms, which means standards.
25. Example
Examples of distributed systems and applications of distributed
computing include the following….
Telecommunication Networks:
telephone networks and cellular networks
computer networks such as the Internet
wireless sensor networks
routing algorithms
Network Applications:
World Wide Web and peer-to-peer networks
massively multiplayer online games and virtual reality communities,
distributed databases and distributed database management systems
Network file systems
26. real-time process control:
aircraft control systems
industrial control systems
parallel computation:
scientific computing, including cluster computing and grid
computing and various volunteer computing projects (see
the list of distributed computing projects),
distributed rendering in computer graphics
27. Advantages
Give more performance than single system
If one pc in distributed system malfunction or
corrupts then other node or pc will take care of
More resources can be added easily
Resources like printers can be shared on multiple pc’s
28. Disadvantages
Security problem due to sharing
Some messages can be lost in the network system
Bandwidth is another problem if there is large data then
all network wires to be replaced which tends to become
expensive
Overloading is another problem in distributed operating
systems
If there is a database connected on local system and
many users accessing that database through remote or
distributed way then performance become slow
The databases in network operating is difficult to
administrate then single user system
29. Conclusion
• In this age of optimization everybody is trying to get
optimized output from their limited resources. The
concept of distributed computing is the most efficient
way to achieve the optimization. In case of distributed
computing the actual task is modularized and is
distributed among various computer system. It not
only increases the efficiency of the task but also
reduce the total time required to complete the task.