Cloud computing

SIno Topics Page no
1 Introduction 4

2 Concepts 5
2.1 Cyber infrastructure
2.2 Service-Oriented Architecture

3 Cloud Architecture 7
3.1 Cloud Types

4 Component 9
4.1 Virtualization
4.2 Users

5 Working 10

6 Merits and Demerits 11

7 Conclusion 12

8 References 13

1.INTRODUCTION
Cloud computing is the next natural step in the evolution of on-demand information
technology services and products. To a large extent cloud computing will be based on
virtualized resources. The idea of cloud computing is based on a very fundamental
principal of `reusability of IT capabilities`. The difference that cloud computing brings
compared to traditional concepts of ―grid computing‖ , ―distributed computing‖ ,
―utility computing‖ , or ―autonomic computing‖ is to broaden horizons across
organizational boundaries.

According to the IEEE Computer Society Cloud Computing is:

"A paradigm in which information is permanently stored in servers on the
Internet and cached temporarily on clients that include desktops,
Entertainment centers, table computers, notebooks, wall computers, handhelds, etc."

Though many cloud computing architectures and deployments are powered by grids,
based on autonomic characteristics and consumed on the basis of utilities billing, the
concept of a cloud is fairly distinct and complementary to the concepts of grid, SaaS,
Utility Computing etc. In theory, cloud computing promises availability of all required
hardware, software, platform, applications, infrastructure and storage with an
ownership of just an internet connection.

people can access the information that they need from any device with an Internet
connection—including mobile and handheld phones—rather than being chained to the
desktop. It also means lower costs, since there is no need to install software or
hardware.‖

Cloud computing used to posting and sharing photos on orkut, instant messaging with
friends maintaining and upgrading business technology

2. Concepts
A powerful underlying and enabling concept is computing through service-oriented
architectures (SOA) - delivery of an integrated and orchestrated suite of functions to an
end-user through composition of both loosely and tightly coupled functions, or services -
often network based. Related concepts are component-based system engineering,
orchestration of different services through workflows, and virtualization.

2.1. Cyber infrastructure

Cyber infrastructure makes applications dramatically easier to develop and deploy, thus
expanding the feasible scope of applications possible within budget and organizational
constraints, and shifting the scientist’s and engineer’s effort away from information
technology development and concentrating it on scientific and engineering research. Cyber
infrastructure also increases efficiency, quality, and reliability by capturing commonalities
among application needs, and facilitates the efficient sharing of equipment and services.

Today, almost any business or major activity uses, or relies in some form, on IT and IT
services. These services need to be enabling and appliance-like, and there must be an
economy of- scale for the total-cost-of-ownership to be better than it would be without cyber
infrastructure. Technology needs to improve end-user productivity and reduce Technology-
driven overhead

2.2. Service-Oriented Architecture

SOA is not a new concept, although it again has been receiving considerable attention in
recent years [e.g., Bel08, IBM08a]. Examples of some of the first network-based service-
oriented architectures are remote procedure calls (RPC), DCOM and Object Request
Brokers (ORBs) based on the CORBA specifications . A more recent example are so called
―Grid Computing‖ architectures and solutions . In an SOA environment end-users
request an IT service (or an integrated collection of such services) at the desired functional,
quality and capacity level, and receive the reponse at the time requested or at a specified
later time. Service discovery, brokering, and reliability are important .Goal of the SOA is
that creating an architecture in which servises are able to communicate using http protocol
It is expected that in the next 10 years, service-based solutions will be a major vehicle for
delivery of information and other IT assisted functions at both individual and
organizational levels.

e.g., software applications, web-based services, personal and business ―desktop‖ computing.

3 Cloud Architecture
Cloud architecture the systems architecture of the software systems involved
in the delivery of cloud computing, comprises hardware and software designed by a cloud
architect who typically works for a cloud integrator. It typically involves multiple cloud
components communicating with each other over application programming interfaces,
usually web services.

This closely resembles the Unix philosophy of having multiple programs doing one thing
well and working together over universal interfaces. Complexity is controlled and the
resulting systems are more manageable than their monolithic counterparts.

Cloud architecture extends to the client, where web browsers and/or software applications
access cloud applications. Cloud storage architecture is loosely coupled, where metadata
operations are centralized enabling the data nodes to scale into the hundreds, each
independently delivering data

Fig.3. Cloud Architecture

3.1. Cloud –Types

Public cloud:
Public cloud or external cloud describes cloud computing in the traditional mainstream.
Public clouds are run by third parties, and applications from different customers are likely
to be mixed together on the cloud’s servers, storage systems, and networks. A public cloud
provides services to multiple customers.

Hybrid cloud:
Hybrid clouds combine both public and private cloud models. This is most often seen with
the use of storage clouds to support Web 2.0 applications.

Private cloud:
Private clouds are built for the exclusive use of one client, providing the utmost
control over data, security, and quality of service (Figure 4). The company owns the
infrastructure and has control over how applications are deployed on it. Private clouds can
be built and managed by a company’s own IT organization or by a cloud provider
.
Cloud computing products and services can be classified into 4 major
categories:
They are
1. Application as service ( AaaS)
2. Platform as a Service (PaaS)
3. Infrastructure as a service (IaaS)
4. Software as a Service (SaaS)

1. Application as s service (AaaS): These are the first kind of cloud computing services that
came into being. Under this, a service is made available to an end-user. The end-user is
asked to create an account with the service provider and start using the application. One of
first famous application was web-based email service by hotmail started in 1996. Scores of
such services are available now on the web.

2. Platform as a Service (PaaS): Cloud vendors are companies that offer cloud computing
services and products. One of the services that they provide is called PaaS. Under this a
computing platform such as operating system is provided to a customer or end user on a

monthly rental basis. Some of the major cloud computing vendor are Amazon, Microsoft,
Google etc

3. Infrastructure as a service: The cloud computing vendors offer infrastructure as a service.
One may avail hardware services such as processors, memory, networks etc on agreed basis
for specific duration and price. 4. Software as a service (SaaS): Software package such as CRM
or CAD/CAM can be accessed under cloud computing scheme. Here a customer upon
registration is allowed to use software accessible through net and use it for his or his business
process. The related data and work may be stored on local machines or with the service
providers. SaaS services may be available on rental basis or on per use basis.

4.Component
The key to a SOA framework that supports workflows is componentization of its services,
an ability to support a range of couplings among workflow building blocks, fault-tolerance
in its data- and process-aware service-based delivery, and an ability to audit processes, data
and results, i.e., collect and use provenance information. Component-based approach is
characterized by reusability (elements can be re-used in other workflows), substitutability
(alternative implementations are easy to insert, very precisely specified interfaces are
available, run-time component replacement mechanisms exist, there is ability to verify and
validate
substitutions, etc), extensibility and scalability (ability to readily extend system component
pool and to scale it, increase capabilities of individual components, have an extensible and
scalable architecture that can automatically discover new functionalities and resources,
etc),customizability (ability to customize generic features to the needs of a particular
scientific domain and problem), and composability (easy construction of more complex
functional solutions using basic components, reasoning about such compositions, etc.).
There are other
characteristics that also are very important. Those include reliability and availability of the
components and services, the cost of the services, security, total cost of ownership, economy
of scale, and so on.In the context of cloud computing we distinguish many categories of
components. From differentiated and undifferentiated hardware, to general-purpose and
specialized software and applications, to real and virtual ―images‖ , to environments, to
no-root
Differentiated resources, to workflow-based environments and collections of services, and
soon.

4.1 Virtualization
Virtualization is another very useful concept. It allows abstraction and isolation of lower-
level functionalities and underlying hardware. This enables portability of higher-level
functions and sharing and/or aggregation of the physical resources. The virtualization
concept has been around in some form since 1960s (e.g., in IBM mainframe systems). Since
then, the concept has matured considerably and it has been applied to all aspects of
computing – memory, storage, processors, software, networks, as well as services that IT
offers. It is the combination of the growing needs and the recent advances in the IT
architectures and solutions that is now
bringing the virtualization to the true commodity level. Virtualization, through its economy of
scale, and its ability to offer very advanced and complex IT services at a reasonable cost, is
poised to become, along with wireless and highly distributed and pervasive computing

devices, such as sensors and personal cell-based access devices, the driving technology behind
the next waive in IT growth .Not surprisingly there are dozens of virtualization products, and a
number of small and large companies that make them. Some examples in the operating
systems and software applications space are VMware1, Xen - an open source Linux-based
product developed

by XenSource2, and Microsoft virtualization products, to mention a few. Major IT players
have also shown a renewed interest in the
technology. Classical storage players such as EMC10, NetApp11, IBM12
and Hitachi13 have not been standing still either. In addition, the network virtualization
market is teeming with activity.

4.2 Users
The most important Cloud entity, and the principal quality driver and constraining
influence is, of course, the user. The value of a solutions depends very much on the view it
has of its end-user requirements and user categories.

There four broad sets of nonexclusive user categories:
System or Cyber infrastructure (CI) developers, developers (authors) of different component
services and underlying applications, technology and domain personnel that integrates basic
services into composite services and their orchestrations (workflows) and delivers those to
end-users, and finally users of simple and composite services. User categories also include
domain specific groups, and indirect users such as stakeholders, policy makers, and so on.
Functional and usability requirements derive, in most part, directly from the user profiles.

Working Of Cloud Computing:
Cloud Computing system can be divided it into two sections: the front end and the back
end. They connect to each other through a network, usually the Internet. Thefront end is
the side the computer user, or client, sees.The back end is the "cloud" section of the system.
On the back end there are various computers,servers and data storage systems that create
the "cloud" of
computing services.A central server administers the system, monitoring traffic and client
demands to ensure everything runs smoothly. It followsa set of rules called protocols
Servers and remote computers do most of the work and store the data.

6. Merits & Demerits:

Merits:
Cloud enabler technologies like utility computing, Grid Computing, RTI, web
infrastructure and others are cloud enabled.

1. Infrastructure service providers are taking advantage of the Cloud services.

2. Information services, entertainment-oriented services such as video on demand, simple
business services such as customer authentication or identity management and contextual
services such as location or mapping services are positioned well by using the service.

3. Other services, such as corporate processes (for example, billing, deduction management
and mortgage calculation) and transactional services (for example, fiscal transactions),
would take longer to reach the cloud and the mainstream.

4. Cloud computing infrastructures allows efficient use of their IT hardware and software
investments

5. A cloud infrastructure can be a cost efficient model for delivering information services,
reducing IT management complexity.

6. The Cloud makes it possible to launch Web 2.0 applications quickly and to scale up
applications as much as needed when needed.

Demerits:
Stored data might not be secure: With cloud computing, all our data is stored on the cloud.
The unauthorized users gain access to our confidential data.

Dependent on internet connection:Internet connectivity isn’t completely stable and reliable.

It’s not platform agnostic:Most clouds force participants to rely on a single platform or host
only one type of product.

Can be slow:Even on a fast connection,web based application scan sometimes be slower than
accessing a similar software program on our desktop PC

7.Conclusion
―Cloud‖ computing builds on decades of research in virtualization, distributed
computing, utility computing, and more recently networking, web and software services. It
implies a service oriented architecture, reduced information technology overhead for the
end-user, great flexibility, reduced total cost of ownership, ondemand services and many
other things.
In today's global competitive market, companies must innovate and get the most from its
resources to succeed. Cloud computing infrastructures are next generation platforms that
can provide tremendous value to companies of any size. They can help companies achieve
more efficient use of their IT hardware and software investments and provide a means to
accelerate the adoption of innovations.Cloud computing increases profitability by
improving resource utilization. Costs are driven down by delivering appropriate resources
only for the time those resources are needed. Cloud computing has enabled teams and
organizations to streamline lengthy procurement processes.
Cloud computing enables innovation by alleviating the need of innovators to find resources to
develop, test, and make their innovations available to the user community. Innovators are
free to focus on the innovation rather than the logistics of finding and managing resources
that enable the innovation.

8. References
Magazines:

1] Cloud Computing – MLADEN .A.VOUK -Issues, Research an Implementations ,
Information Technical Interfaces ,june 2008

Websites:

www.ibm.com/developerworks/websphere/zones/hipods/library.html

http://communication.howstuffworks.com/cloud-computing2.html

www.thbs.com

http://www.wikipedia.org/

Cloud computing

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