1. CLOUD COMPUTING
Submitted by
J.Meghana (1BM12TE401)

2. Introduction
Let's say you're an executive at a large corporation. Your particular responsibilities
include making sure that all of your employees have the right hardware and software they need to do
their jobs. Buying computers for everyone isn't enough -- you also have to purchase software or
software licenses to give employees the tools they require. Whenever you have a new hire, you have
to buy more software or make sure your current software license allows another user. It's so stressful
that you find it difficult to go to sleep on your huge pile of money every night
Soon, there may be an alternative for executives like you. Instead of installing a suite of
software for each computer, you'd only have to load one application. That application would allow
workers to log into a Web-based service which hosts all the programs the user would need for his or
her job. Remote machines owned by another company would run everything from e-mail to word
processing to complex data analysis programs. It's called cloud computing, and it could change the
entire computer industry.
Cloud computing is a technology that uses the internet and central remote servers to
maintain data and applications. Cloud computing allows consumers and businesses to use applications
without installation and access their personal files at any computer with internet access. This
technology allows for much more efficient computing by centralizing storage, memory, processing
and bandwidth.
A simple example of cloud computing is Yahoo email or Gmail etc. You don‘t
need a software or a server to use them. All a consumer would need is just an internet
connection and you can start sending emails.
History
Once upon a time, it seems people were dreaming about computer as a utility.
• Computation and storage would be used as a public service provided by professionals
• End users would not experience the ―joy‖ of software installation and administration
Initial traces of cloud computing go to John McCarthy (back in the 1960s!), who
proposed that computers may someday be organized in a method that would involve it acting
as a public utility.
However, it we had to wait until the 1999s to actually experience this in practice!

3. Traditional business applications have always been very complicated and expensive.
The amount and variety of hardware and software required to run them are daunting. You
need a whole team of experts to install, configure, test, run, secure, and update them
With cloud computing, you eliminate those headaches because you‘re not managing
hardware and software—that‘s the responsibility of an experienced vendor like
salesforce.com. The shared infrastructure means it works like a utility: You only pay for what
you need, upgrades are automatic, and scaling up or down is easy.
Cloud-based apps can be up and running in days or weeks, and they cost less. With a
cloud app, you just open a browser, log in, customize the app, and start using it.
Businesses are running all kinds of apps in the cloud, like customer relationship
management (CRM), HR, accounting, and much more. Some of the world‘s largest
companies moved their applications to the cloud with salesforce.com after rigorously testing
the security and reliability of our infrastructure.
Layers:
Client
A cloud client consists of computer hardware and/or computer software that relies on cloud
computing for application delivery and that is in essence useless without it. Examples include some
computers, phones and other devices, operating systems, and browsers.
Application
Cloud application services or "Software as a Service (SAAS)" deliver software as a service over the
Internet, eliminating the need to install and run the application on the customer's own computers and
simplifying maintenance and support.
1. SAAS
This type of cloud computing delivers a single application through the browser to
thousands of customers using a multitenant architecture. On the customer side, it means no
upfront investment in servers or software licensing; on the provider side, with just one app to
maintain, costs are low compared to conventional hosting. Salesforce.com is by far the bestknown example among enterprise applications, but SAAS is also common for HR apps and
has even worked its way up the food chain to ERP, with players such as Workday. And who
could have predicted the sudden rise of SAAS"desktop" applications, such as Google Apps
and Zoho Office?
Platform

4. Cloud platform services, also known as platform as a service (PAAS), deliver a computing
platform and/or solution stack as a service, often consuming cloud infrastructure and sustaining cloud
applications. It facilitates deployment of applications without the cost and complexity of buying and
managing the underlying hardware and software layers.
2. PAAS
Another SAAS variation, this form of cloud computing delivers development
environments as a service. You build your own applications that run on the provider's
infrastructure and are delivered to your users via the Internet from the provider's servers. Like
Legos, these services are constrained by the vendor's design and capabilities, so you don't get
complete freedom, but you do get predictability and pre-integration. Prime examples include
Salesforce.com'sForce.com, Coghpead and the new Google App Engine. For extremely
lightweight development, cloud-based mash up platforms abound, such as Yahoo Pipes or
Dapper.net
Infrastructure
Cloud infrastructure services, also known as "infrastructure as a service" (IAAS), deliver computer
infrastructure – typically a platform virtualization environment – as a service, along with raw (block)
storage and networking. Rather than purchasing servers, software, data-center space or network
equipment, clients instead buy those resources as a fully outsourced service. Suppliers typically bill
such services on a utility computing basis; the amount of resources consumed (and therefore the cost)
will typically reflect the level of activity.
3. IAAS
The IAAS layer extends the virtualization layer by providing the mechanisms to provision
and control the virtual machines in a utility computing manner. By this I mean that a common
interface, such as a web portal, or an exposed API allows the end user to build and configure
virtual machine templates as needed. The end user can also control when to turn on or destroy
virtual machines and define how the virtual machines are networked with each other. If the
IAAS is provided in a utility computing model, then the end user is also able to control cost
by knowing exactly how much each virtual machine instance costs per minute/hour. Some
vendors in this layer also provide storage and database services which are controlled via an
exposed API as well. These services are typically billed in a utility computing fashion too. A
lot can be done at this layer with respect to automation and orchestration (topics I will discuss
in later articles) but the bulk of it is left up to the end user to handle. A good example of a
major player in this space is Amazon Web Services with the EC2, S3 and Database services
Server
The server‘s layer consists of computer hardware and/or computer software products that are
specifically designed for the delivery of cloud services, including multi-core processors, cloudspecific operating systems and combined offerings

5. Issues
Security
While a leading edge cloud services provider will employ data storage and
transmission encryption, user authentication, and authorization (data access) practices, many
people worry about the vulnerability of remote data to such criminals as hackers, thieves, and
disgruntled employees. Cloud providers are enormously sensitive to this issue and apply
substantial resources to mitigating concern.
Reliability
Some people worry also about whether a cloud service provider is financially stable
and whether their data storage system is trustworthy. Most cloud providers attempt to mollify
this concern by using redundant storage techniques, but it is still possible that a service could
crash or go out of business, leaving users with limited or no access to their data. A
diversification of providers can help alleviate this concern, albeit at a higher cost.
Ownership
Once data has been relegated to the cloud, some people worry that they could lose
some or all of their rights or be unable to protect the rights of their customers. Many cloud
providers are addressing this issue with well-crafted user-sided agreements. That said, users
would be wise to seek advice from their favorite legal representative. Never use a provider
who, in their terms of service, lays any kind of ownership claim over your data.
Data Backup
Cloud providers employ redundant servers and routine data backup processes, but
some people worry about being able to control their own backups. Many providers are now
offering data dumps onto media or allowing users to back up data through regular downloads.
Data Portability and Conversion
Some people are concerned that, should they wish to switch providers, they may have
difficulty transferring data. Porting and converting data is highly dependent on the nature of
the cloud provider‘s data retrieval format, particular in cases where the format cannot be
easily discovered. As service competition grows and open standards become established, the
data portability issue will ease, and conversion processes will become available supporting
the more popular cloud providers. Worst case, a cloud subscriber will have to pay for some
custom data conversion.

6. Multiplatform Support
More an issue for IT departments using managed services is how the cloud-based
service integrates across different platforms and operating systems, e.g. OS X, Windows,
Linux and thin-clients. Usually, some customized adaption of the service takes care of any
problem. Multiplatform support requirements will ease as more user interfaces become webbased.
Intellectual Property
A company invents something new and it uses cloud services as part of the invention.
Is the invention still patentable? Does the cloud provider have any claim on the invention?
Can they provide similar services to competitors? All good questions and answerable on a
case-by-case basis.
Types of cloud computing
Public cloud
Public cloud is the most popular type of cloud system and is considered as a mainstream cloud system by cloud computing experts. In public cloud system a third party data
center provide both disk space and computing power for all the application software. Amazon
web and Google apps is the two most popular public cloud computing service providers.
Private cloud
Private cloud unlike public cloud, you need to set up your own data center and also
bear all the installation & maintenance cost, and have complete control of all your data. This
system provides more security and privacy, but it is more expensive cloud solution to public
cloud.
Hybrid cloud
Hybrid cloud is a cloud computing environment in which an organization provides and
manages some resources in-house and has others provided externally. For example, an organization
might use a public cloud service, such as Amazon Simple Storage Service (Amazon S3) for archived
data but continue to maintain in-house storage for operational customer data. Ideally, the hybrid
approach allows a business to take advantage of the scalability and cost-effectiveness that a public
cloud computing environment offers without exposing mission-critical applications and data to thirdparty vulnerabilities. This type of hybrid cloud is also referred to as hybrid IT.

7. Advantage
Easy implementation process:
Cloud hosting offers you a readily available internet based infrastructure already there
which can be made available to the enterprise in least possible time. The biggest benefit for
the enterprise lies in the costs avoided in terms of the IT infrastructure minimization, nonrequirement of a dedicated technical IT support and management team. Thus in a way cloud
hosting allows you to have the same application and business process implemented without
actually investing in the backend technical complexities.
Service "rented out" on "pay as you go" model:
Cloud hosting model is essentially based on the principle of pay as you go model.
Thus you are not penalized for the unused IT infrastructure that a cloud host may have but
you are assured of the availability of the infrastructure at a very short notice. This implies that
technology costs and risks are being shared by the services provider. This essentially means
that the enterprise is absolved of the scalability and provisioning issues. Besides this the cloud
hosting minimizes the barriers to entry for small business as earlier the same technological
process required tremendous capital expenditure , beyond the capability of small and medium
business.
Cost Per head:
Cloud hosting services ensures that the overhead technology costs are kept at a
minimum so that resources liberated from the IT infrastructure setup and management can be
used for improving the business focus of the enterprise.
Accessibility of the application:
Internet cloud infrastructure ensures that your application is accessible from anyplace
anytime and thus real time collaboration and sharing becomes a reality which can be
leveraged for the enterprise productivity and efficiency.
Troubleshooting, Installation and configuring the software:
Cloud hosting also means that the application management is easy and optimal
utilization guaranteed as the service provider installation, upgrades as well as monitor the
application in real time in relation to software as well as customizes the environment as per
the customer's requirement. Finally 24x7x365 IT troubleshooting is also provided by the
service provider which further reduces the application process "Operating costs" Visit Real
Time Data Services for more details.

8. Disadvantage
If you are going to move all of your information to data centers situated outside your company,
then security should be of utmost importance.

Lost control comes with handing over your data and information

Depending on third-party to ensure the security and confidentiality of data and information
 If your cloud host disappears, where does your information go?
Conclusion
 Cloud computing is truly a revolutionary concept for many business0 organizations. Because
of the technology's ease of adoption
 Significantly lower maintenance cost ‗s, and greater workflow efficiency
 There is no doubt that cloud computing will gain widespread popularity going forward