CLOUD COMPUTING – AN OVERVIEW

BY -SHASHANK SHEKHAR

B.Tech II yearSathyabama university

E-mail id- shashankshekhar114@gmail.com

Cloud Computing is a type of internet based computing where different services such as servers, storage and application are delivered to an organisation’s computer or devices through internet.

Cloud Computing is document centric - documents are not stored in ones individual computer but on a server which can be accessed by any one via internet.

Examples of cloud computing includes:- • Online file storage• Social networking sites• Webmail and online business app

sINTRODUCION

CHARACTERISTICS

Common Characteristics:

Low Cost Software

Virtualization Service Orientation

Advanced Security

Homogeneity

Massive Scale Resilient Computing

Geographic Distribution

Essential Characteristics:

Resource Pooling

Broad Network Access Rapid Elasticity

Measured Service

On Demand Self-Service

ARCHITECTURE & SERVICE MODELS

CLOUD SERVICE MODELSSoftware as a

Service (SaaS)Platform as a

Service (PaaS)Infrastructure as a Service (IaaS)

Google App Engine

•SalesForce CRM• LotusLive

SOFTWARE AS A SERVICE (SAAS)

In the Saas model, the cloud providers install and operate application software in the cloud and cloud user access the software from the cloud clients. The user does not need to install and run the application so it simplifies maintenance and support.

In Saas the user are not required to handle software upgrades and patches. Software is delivered in a one to many models.

With Saas it is easy for enterprises to streamline their maintenance and support because everything is managed by vendors

Examples of SaaS include SalesForce.com, Google Mail, Google Docs, and so forth

PLATFORM AS A SERVICE (PAAS )-

It offers runtime environment or platform to create and deploy. The organisation is responsible for development, management and maintenance of the application.

It makes the development, testing and deployment of application quick, simple and cost effective.

The drawback of this model is that it lacks interoperateability and portability among providers. If we create an app in one cloud we cannot move it into another cloud we need to pay a higher price for it.

Eg. Windows azure, Google app engine, mendix, engine guard, orangespace etc.

INFRASTRUCTURE AS A SERVICE (IAAS

It is the most basic cloud- service model, provides computer physical or virtual machines and other resources.

It offers additional resources such as a virtual machine disk-image library, raw and file based storage, fireworks, IP addresses, VLANs and software bundles.

Eg. Amazon EC2, azure services, Google computer engines, HP cloud, Oracle.

It makes the acquisition of hardware’s easier. Rather than purchasing the server, storage, OS it can be accessed through internet.

SERVICE MODELS CONT...

TYPES OF CLOUD -

There are many issues to consider when moving an enterprise application to the cloud environment. For example, some

service providers are mostly interested in lowering operation cost, while others may prefer high reliability and security.

Accordingly, there are different types of clouds, each with its own benefits and drawbacks:-

• Public clouds• Private clouds• Hybrid clouds

TYPES OF CLOUD- PUBLIC CLOUD –

• A cloud in which service providers offer their resources as services to the general public.

• Public clouds offer several key benefits to service providers, including no initial capital investment on infrastructure and shifting of risks to infrastructure providers.

• public clouds lack fine-grained control over data, network and security settings, due to which their effectiveness is hampered.

PRIVATE CLOUD –• Also known as internal clouds, private clouds are

designed for exclusive use by a single organization.

TYPES OF CLOUD CONT..-• A private cloud offers the highest degree of control over

performance, reliability and security. HYBRID CLOUD –

• A hybrid cloud is a combination of public and private cloud models that tries to address the limitations of each approach.

• In a hybrid cloud, part of the service infrastructure runs in private clouds while the remaining part runs in public clouds.

• Hybrid clouds offer more tighter control, flexibility and security than both public and private clouds.

• Designing a hybrid cloud requires carefully determining the best split between public and private cloud components.

ADVANTAGES

Lower-Cost Computers for Users - • Since applications run in the cloud, not on the desktop PC, so

desktop PC does no need the processing power or hard disk space demanded by traditional desktop software.

Lower Software Costs –• Instead of purchasing expensive software applications, we can

get most of what we need for free.

Instant Software Updates –• Another advantage to cloud computing is that

you are no longer faced with choosing between obsolete software and high upgrade costs.

• When the application is web-based, updates happen automatically

ADVANTAGES

Unlimited Storage Capacity –• Cloud computing offers virtually limitless storage of

nearly hundreds of Pbytes.

Increased Data Reliability • It is data centric so even if our PC crashes, all your data

is still out there in the cloud, still accessible

Universal Access to Documents -• That is not a problem with cloud computing, because

you do not take your documents with you. • Instead, they stay in the cloud, and you can access

them whenever you have a computer and an Internet connection

ADVANTAGES Latest Version Availability

• The cloud always hosts the latest version of our documents, it will automatically update it without users knowledge.

Improved Performance –• Computers in a cloud computing system boot and run

faster because they have fewer programs and processes loaded into memory.

Easier group collaboration:• Sharing documents leads directly to better

collaboration. Many users do this as it is an important advantages of

cloud computing

ADVANTAGES

Device independence - • we are no longer tethered to a single computer or

network. Even on moving to a portable device,our applications

and documents are still available.

Improved document format compatibility. • You do not have to worry about the documents you create on

your machine being compatible with other users' applications or OS.

• There are potentially no format incompatibilities when everyone is sharing documents and applications in the cloud.

DISADVANTAGES Requires a constant Internet connection-

• Cloud computing is impossible if there is no Internet connection.

• A dead Internet connection means no work and in areas where Internet connections are few or inherently unreliable, this could be a deal-breaker.

Does not work well with low-speed connections: • Web-based applications require a lot of bandwidth to

download, as do large documents.

General Concerns: Each cloud systems uses different protocols and different

APIs It may not be possible to run applications between

different cloud based systems.

DISADVANTAGES - Features might be limited:

• This situation is bound to change, but today many web-based applications simply are not as full-featured as their desktop-based applications.

• For example, we can do a lot more with Microsoft PowerPoint than with Google Presentation's web-based offering.

Stored data might not be secure:• With cloud computing, all your data is stored on the

cloud but unauthorized users can gain access to our confidential data.

Stored data can be lost: Theoretically, data stored in the cloud is safe,

replicated across multiple machines.

PROVIDERS OF CLOUD COMPUTING

CHALLENGES

o Automated service provisioningo Virtual machine migration o Server consolidationo Energy managemento Traffic management and analysiso Data security

CONCLUSION

Cloud computing has recently emerged as a compelling paradigm for managing and delivering services over the Internet.

The rise of cloud computing is rapidly changing the landscape of information technology, and ultimately turning the long-held promise of utility computing into a reality.

However, despite the significant benefits offered by cloud computing, the current technologies are not matured enough to realize its full potential.

REFERENCES

Armbrust M et al (2009) Above the clouds: a Berkeley view of cloud computing. UC Berkeley Technical Report

NIST Definition of cloud computing (csrc.nist.gov/groups/SNS/cloud- computing/cloud-def-v15.doc)

http://en.wikipedia.org/wiki/Cloud_computing http://aws.amazon.com/ec2 Windows Azure, www.microsoft.com/azure http://code.google.com/appengine