WHAT IS ?
Cloud computing is a type of computing that relies on sharing computing
resources rather than having local servers or personal devices to handle
Describes a variety of different computing concepts that involve a large number
of computers that are connected through a real-time communication network
(typically the Internet).
At the foundation of cloud computing is the broader concept of converged
infrastructure and shared services.
Cloud computing is comparable to grid computing, a type of computing where
unused processing cycles of all computers in a network are harnesses to solve
problems too intensive for any stand-alone machine.
Cloud computing is an umbrella term used to refer to Internet based
development and services
A number of characteristics define cloud data, applications services
Remotely hosted: Services or data are hosted on remote
Ubiquitous: Services or data are available from anywhere.
Commodified: The result is a utility computing model similar to
traditional that of traditional utilities, like gas and electricity - you
pay for what you would want!
Cloud Computing Characteristics
Low Cost Software
Virtualization Service Orientation
Massive Scale Resilient Computing
Broad Network Access Rapid Elasticity
On Demand Self-Service
Cloud Computing Architecture
There are two sections: the front end and the back end. They connect to each
other through a network, usually the Internet.
The front end includes the client's computer (or computer network) and the
application required to access the cloud computing system.
On the back end of the system are the various computers, servers and data
storage systems that create the "cloud" of computing services.
A cloud computing system can include any computer program. Its based on a
technique called server virtualization. Usually, each application will have its
own dedicated server.
A central server administers the system, monitoring traffic and client demands
to ensure everything runs smoothly.
Cloud Computing Architecture
A central server follows a set of rules called protocols and uses a special kind
of software called middleware.
Middleware allows networked computers to communicate with each other.
A Cloud Computing System follows Data Redundancy which enables the
central server to access backup machines to retrieve data.
Server Virtualisation : It's possible to fool a physical server into thinking it's
actually multiple servers, each running with its own independent operating
system. The technique is called server virtualization.
By maximizing the output of individual servers, server virtualization reduces
the need for more physical machines.
App App App
App App App
VM technology allows multiple virtual machines to
run on a single physical machine.
Virtual Machine Monitor (VMM) / Hypervisor
VM VM VM
Performance: Para-virtualization (e.g. Xen) is very close to raw physical performance!
Examples: Amazon’s EC2, GoGrid, AppNexus
Platform as a Service (PaaS)
Example: Google App Engine
Software as a Service (SaaS)
Storage Platform Amazon S3, Dell, Apple, ...
3Tera, EC2, SliceHost,
GoGrid, RightScale, Linode
Google App Engine, Mosso,
Force.com, Engine Yard,
Facebook, Heroku, AWS
MS Live/ExchangeLabs, IBM,
Google Apps; Salesforce.com
Quicken Online, Zoho, Cisco
HOW CLOUD COMPUTING WORKS?
To accomplish its goals, cloud computing uses networks of large groups
of servers typically running low-cost consumer PC technology with
specialized connections to spread data-processing chores across them.
This shared IT infrastructure contains large pools of systems that are
Often, virtualization techniques are used to maximize the power of
BASIC CLOUD CHARACTERISTICS
1. The “no-need-to-know” in terms of the underlying details of
infrastructure, applications interface with the infrastructure via the
1. The “flexibility and elasticity” allows these systems to scale up and
down at will
1. utilising the resources of all kinds
2. CPU, storage, server capacity, load balancing, and databases
2. The “pay as much as used and needed” type of utility computing
and the “always on!, anywhere and any place” type of network-
BASIC CLOUD CHARACTERISTICS
Cloud are transparent to users and applications, they can be built in
branded products, proprietary open source, hardware or software,
or just off-the-shelf PCs.
In general, they are built on clusters of PC servers and off-the-shelf
components plus Open Source software combined with in-house
applications and/or system software
Several large Web companies are now exploiting
the fact that they have data storage capacity that
can be hired out to others.
allows data stored remotely to be temporarily cached on
desktop computers, mobile phones or other Internet-
Amazon’s Elastic Compute Cloud (EC2) and
Simple Storage Solution (S3) are well known
APPLICATIONS OF CLOUD COMPUTING
They could access the cloud computing system using any computer linked to
the Internet. Data wouldn't be confined to a hard drive or any internal
It could bring hardware costs down. Cloud computing systems would reduce
the need for advanced hardware on the client side.
Cloud computing gives these companies the option of storing data on someone
else's hardware, removing the need for physical space on the front end.
If the cloud computing system's back end is a grid computing system, then the
client could take advantage of the entire network's processing power.
Corporations might save money on IT support. Streamlined hardware would,
in theory, have fewer problems than a network of heterogeneous machines
and operating systems
GOALS OF CLOUD COMPUTING
To apply traditional supercomputing, or high-performance computing
power normally used by military and research facilities.
To perform tens of trillions of computations per second, in consumer-
oriented applications such as financial portfolios.
To deliver personalized information.
To provide data storage or to power large, immersive computer games.
Cloud Computing Concerns
Security : Corporate executives might hesitate to take advantage of a
cloud computing system because they can't keep their company's
information under lock and key. The counterargument to this position
is that the companies offering cloud computing services live and die by
their reputations. It benefits these companies to have reliable security
measures in place.
Privacy : Cloud computing companies will need to find ways to
protect client privacy. One way is to use authentication techniques
such as user names and passwords. Another is to employ an
authorization format -- each user can access only the data and
applications relevant to his or her job.
ADVANTAGES OF CLOUD COMPUTING
Used in marketing to sell hosted services in the sense of application service
provisioning that run client server software on a remote location.
It allows users the mobility necessary in this day and age of global marketing.
Versatile Compatibility : Users are often surprised to find that the various
cloud apps available are accessible on both platforms.
Cloud allows users to literally get what they pay for. This scalability allows for
you to simply purchase the applications and data storage you really need.
Individuality : One of the most convenient aspects of working in the cloud is
that it is compatible with aspects specific to the company. For example, cloud IT
services can be scaled to meet changing system demands within a single
DISADVANTAGE OF CLOUD COMPUTING
Less Control : Utilising the public cloud in business does have an obvious
downside. By using this technology you risk losing a level of control over
Not Always Enough Room : Many have been disappointed with cloud
technology, because they find that once they have instituted a cloud
system within their business, they run out of storage space.
Security and Confidentiality : Cloud computing does pose the risk of
increased security threats. While most companies have an up-to-date virus
database, this does not make the files and information stored in the cloud
immune to hackers.
Many of the activities loosely grouped together under cloud computing
have already been happening and centralised computing activity is not
a new phenomena.
Grid Computing was the last research-led centralised approach.
However there are concerns that the mainstream adoption of cloud
computing could cause many problems for users.
Many new open source systems appearing that you can install and run
on your local cluster
should be able to run a variety of applications on these systems.