1. A REPORT
ON
CLOUD COMPUTING
BY
ABDUL-REHMAN ASLAM
August 8, 2012
PREPARED FOR
MR. SAFEE (COURSE INSTRUTOR)

2. Table Of Contents
1. Introduction ………………………………………………………..……3
2. What is Cloud Computing ? ………….………………………………… 4
3. Cloud Service Model ……………………………………………………. 5
4. Types of Clouds …..……………………………………………………. 6
5. Key Characteristics …..…………………………………………………. 8
6. Conclusion ….……………………………………………………………. 10
7. References ..………………………………………………………………. 11

3. 1. Introduction
Imagine yourself in the world where the users of the computer of today’s internet
world don’t have to run, install or store their application or data on their own
computers, imagine the world where every piece of your information or data would
reside on the Cloud (Internet).
As a metaphor for the Internet, "the cloud" is a familiar cliché, but when
combined with "computing", the meaning gets bigger and fuzzier. Some analysts
and vendors define cloud computing narrowly as an updated version of utility
computing: basically virtual servers available over the Internet. Others go very
broad, arguing anything you consume outside the firewall is "in the cloud",
including conventional outsourcing.
Cloud computing comes into focus only when you think about what we
always need: a way to increase capacity or add capabilities on the fly without
investing in new infrastructure, training new personnel, or licensing new software.
Cloud computing encompasses any subscription-based or pay-per-use service that,
in real time over the Internet, extends ICT's existing capabilities.
Cloud computing is at an early stage, with a motley crew of providers large
and small delivering a slew of cloud-based services, from full-blown applications
to storage services to spam filtering. Yes, utility-style infrastructure providers are
part of the mix, but so are SaaS (software as a service) providers such as
Salesforce.com. Today, for the most part, IT must plug into cloud-based services
individually, but cloud computing aggregators and integrators are already
emerging.

4. 2. What is Cloud Computing
Cloud computing is the delivery of computing and storage capacity as a service to
a community of end-recipients.
OR
In cloud computing, the word "cloud" is used as a metaphor for "the Internet," so
the phrase cloud computing is used to mean 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.
OR
Cloud Computing is providing services on virtual machines allocated on lap of
large physical machine.

5. 3. Cloud Computing Service Model
Three core options compose the service model within the cloud computing
environment. Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and
Software as a Service (SaaS).
1.Infrastructure as a Service (IaaS)
The IaaS layer offers storage and compute resources that developers and IT
organizations can use to deliver business solutions.
2.Platform as a Service (PaaS)
The PaaS layer offers black-box services with which developers can build
applications on top of the compute infrastructure. This might include developer
tools that are offered as a service to build services, or data access and database
services, or billing services.
Software as a Service (SaaS)
In the SaaS layer, the service provider hosts the software so you don’t need to
install it, manage it, or buy hardware for it. All you have to do is connect and use
it. SaaS Examples include customer relationship management as a service.

6. 4. Types of Clouds
Cloud Computing can broadly be classified into 4 types. They are
Public Cloud
Private Cloud
Hybrid Cloud
Community Cloud
The types of cloud mentioned above are based on the type of application and
environment being considered before developing the application and on the basis
of the location where it’s been hosted.
Public Cloud
The name “public” in the public cloud comes from the fact that application is
hosted on the Hosting Providers location (Vendors). Though it is hosted in shared
system, each resource operates in silo and encrypted securely. With Public Cloud
all the resources and the services are dynamically added and removed (Scalable)
based on the usage. Public cloud is more advantages for Small and Medium scale
industries since we are going to pay for the resources which we are going to use
and specifically the hardware and the bandwidth are going to be maintained by the
hosting provider. Some of the examples of Public Cloud in market are Amazon
Web Services, Microsoft Azure and Google Apps.
Private Cloud
In this form, the cloud is deployed with in a corporate firewall and runs on premise
IT infrastructure. Private cloud is more expensive compared to the public cloud
since the operating and bandwidth costs are to be maintained by the organization,
but this cloud is more secure than the public cloud. Private Cloud provides more
benefits to the corporate by capitalizing on the Data Security and Corporate
Governance and provides administrators more control over the operating
environment.

7. Hybrid Cloud
Hybrid Cloud are increasingly being used by corporations where there is a need to
maintain some of their applications on their internal infrastructure (because of
regulatory compliance or sensitivity of data), but also need the scalability and cost
benefits of the public cloud.
Cloud bursting is the term normally used for this type of environment where
internal applications are deployed on private cloud for normal usage while internet
applications are deployed on the public cloud to handle variable loads.
Community Cloud
This type of cloud is specifically used for organizations that are shared such as
different government organizations. In this case, non-government organizations
will not have access to this cloud. The cloud could be located in-house, or on
public cloud based on the needs of the organization.

8. 5. Key characteristics
The Followings are key Characteristics of Cloud Computing
1.Cost
Cost is greatly reduced and capital expenditure is converted to operational
expenditure. This lowers barriers to entry, as infrastructure is typically
provided by a third-party and does not need to be purchased for one-time or
infrequent intensive computing tasks. Pricing on a utility computing basis is
fine-grained with usage-based options and minimal or no IT skills are
required for implementation.
2.Device and location independence
Cloud computing enable users to access systems using a web browser
regardless of their location or what device they are using, e.g., PC, mobile.
As infrastructure is off-site (typically provided by a third-party) and
accessed via the Internet the users can connect from anywhere.
3.Multi-tenancy
Cloud computing enables sharing of resources and costs among a large pool
of users, allowing for:
o Centralization of infrastructure in areas with lower costs (such as real
estate, electricity, etc.)
o Peak-load capacity increases (users need not engineer for highest
possible load-levels)
o Utilization and efficiency improvements for systems that are often
only 10-20% utilized.
4.Reliability
Reliability improves through the use of multiple redundant sites, which
makes it suitable for business continuity and disaster recovery. Nonetheless,
most major cloud computing services have suffered outages and IT and
business managers are able to do little when they are affected.

9. 5.Scalability
Scalability via dynamic ("on-demand") provisioning of resources on a fine-
grained, self-service basis near real-time, without users having to engineer
for peak loads. Performance is monitored and consistent and loosely-coupled
architectures are constructed using web services as the system interface.
6.Security
Security typically improves due to centralization of data, increased security-
focused resources, etc., but raises concerns about loss of control over certain
sensitive data. Security is often as good as or better than traditional systems,
in part because providers are able to devote resources to solving security
issues that many customers cannot afford. Providers typically log accesses,
but accessing the audit logs themselves can be difficult or impossible.
7.Sustainability
Sustainability comes about through improved resource utilization, more
efficient systems, and carbon neutrality. Nonetheless, computers and
associated infrastructure are major consumers of energy.

10. 6. Conclusion
Cloud Computing is a vast topic. Cloud Computing is leading the industry’s effort
to bank on this revolutionary technology.
Cloud Computing Brings Possibilities……..
Increases business responsiveness
Accelerates creation of new services via rapid prototyping capabilities
Reduces acquisition complexity via service oriented approach
Uses IT resources efficiently via sharing and higher system utilization
Reduces energy consumption
Handles new and emerging workloads
Scales to extreme workloads quickly and easily
Simplifies IT management
Platform for collaboration and innovation
Cultivates skills for next generation workforce
Today, with such cloud-based interconnection seldom in evidence, cloud
computing might be more accurately described as "sky computing," with many
isolated clouds of services which IT customers must plug into individually. On the
other hand, as virtualization and SOA permeate the enterprise, the idea of loosely
coupled services running on an agile, scalable infrastructure should eventually
make every enterprise a node in the cloud. It's a long-running trend with a far-out
horizon. But among big metatrends, cloud computing is the hardest one to argue
with in the long term.
Cloud Computing is a technology which took the software and business world by
storm. The much deserved hype over it will continue for years to come.

11. 7. References
1.http://en.wikipedia.org/wiki/Cloud_computing
2.http://www.investopedia.com/terms/c/cloud-computing.asp
3.http://cloudblog.8kmiles.com/2012/02/27/cloud-computing-type/
4.http://www.dummies.com/how-to/content/cloud-computing-models.html
5.http://www.esri.com/technology-topics/cloud-gis/service-models.html
6.http://www.google.com.pk/