Cloud Computing

Definition:-Cloud computing provides the facility

to access shared resources and common infrastructure, offering services on demand over the network to perform operations that meet changing business needs.

In Other WordsCloud computing is a general term for

anything that involves delivering hosted services over the Internet.

The name cloud computing was inspired by the cloud symbol that's often used to represent the Internet in flowcharts and diagrams.

“Cloud“ refers to:-�Before we dig further into how does cloud

computing work, first let’s understand what the term “cloud“ refers to.  The concept of �the cloud has been around for a long time in many different incarnations in the business world. It mostly means a grid of computers serving as a service-oriented architecture to deliver software and data.

Other Definitions:-“Cloud computing is an emerging approach to shared

infrastructure in which large pools of systems are linked together to provide IT services.” – IBM press release on “Blue Cloud”

“…a hosted infrastructure model that delivers abstracted IT resources over the Internet” – Thomas Weisel Partners LLC from “Into the Clouds: Leveraging Data Centers and the Road to Cloud Computing”

“Cloud computing describes a systems architecture. Period. This particular architecture assumes nothing about the physical location, internal composition or ownership of its component parts.” – James Urquhart blog post

Defining the Segments:-SaaS

Software as a ServiceStorage as a Service

PaaS – Platform as a ServiceIaaS – Infrastructure as a Service

Cloud Computing Architecture

When talking about a cloud computing system, it's helpful to divide it into two sections: the front end and the back end. They connect to each other through a network, usually the Internet. The front end is the side the computer user, or client, sees. The back end is the "cloud" section of the system.

The Front EndThe front end includes the client's computer (or

computer network) and the application required to access the cloud computing system. Not all cloud computing systems have the same user interface. Services like Web-based e-mail programs leverage existing Web browsers like Internet Explorer or Firefox And Gmail, Facebook etc . Other systems have unique applications that provide network access to clients.

The Back EndOn the back end of the system are the

various computers, servers and data storage systems that create the "cloud" of computing services. In theory, a cloud computing system could include practically any computer program you can imagine, from data processing to video games. Usually, each application will have its own dedicated server.

In New AgeCloud computing has been changing how

most people use the web and how they store their files. It’s the structure that runs sites like Facebook, Amazon and Twitter and the core that allows us to take advantage of services like Google Docs and Gmail. But how does it work?

The key attributes that distinguish cloud computing from conventional computing are:

Compute and storage functions are abstracted and offered as services

Services are built on a massively scalable infrastructure

Services are delivered on demand through dynamic, flexibly configurable resources

Services are easily purchased and billed by consumption

Resources are shared among multiple users (multi-tenancy)

Services are accessible over the Internet or internal network by any device.

Multiple Graphic Descriptions of the “Cloud”

Hosting Industry Ripe for ChangeTechnology has evolvedPeople demand more controlInstant gratificationIn-house too costly from CapEx and Human CapitalColocation for those who want to be physically thereManaged is not dynamic enough

Cloud Computing -“Enabling Technology” to move from Traditional Hosting to Cloud

Hosting

The “Cloud Pyramid”Build upon a foundationLayers equate structureBuilding blocks: Infrastructure,

Platforms, Applications

The “Cloud Pyramid” Inversed1000’s of Cloud Applications currentlyHandful of Cloud PlatformsElite group of Cloud Infrastructure providers

Cloud “Applications”SaaS resides hereMost common Cloud / Many providers of different

servicesExamples: SalesForce, Gmail, Yahoo! Mail, Quicken

OnlineAdvantages: Free, Easy, Consumer AdoptionDisadvantages: Limited functionality, no control or

access to underlying technology

Cloud “Extenders” (Wild Card)Provides extension to Cloud Infrastructure

and Platforms with basic functionalityExamples: Amazon SimpleDB, Amazon SQS,

Google BigTableAdvantages: Extends functionality of

Compute & Storage Clouds to integrate with legacy system or other clouds

Disadvantages: Sometimes requires use of specific Platforms or Infrastructure

Cloud “Aggregators” (Wild Card)Sits on top of various Cloud Infrastructures

for managementExamples: RightScale, AppistryAdvantages: Provides more options for

Cloud environmentsDisadvantages: Dependent on Cloud

Providers