• The Cloud has gained momentum, a concept whose origins lie in clustering and grid computing.

•Clustering. In the past computers were clustered together to form a single larger computer.

•Grid analogy used is of the electricity grid where users can plug into the grid and use a metered utility service. It is similar to the PNG Gas pipeline instead of Gas Cylinders.

Built of 20 SGI Altix clusters, a total of 10240 CPU supercomputer housed at NASA (2004).

Grid computing expands the techniques of clustering where multiple independent clusters act like a grid due to their nature of not being located in a single domain.

Taking Grid further into the service offering, is “The Cloud”.

Cloud computing can also support non-grid environments such as a three-tier Web architecture running standard or Web 2.0 applications.

• Cloud computing is a paradigm of computing in which dynamically scalable and often virtualized resources are provided as service over the Internet.

• Cloud computing is a general term for anything that involves delivering hosted services over the Internet.

• These services are broadly divided into three categories:

– Infrastructure-as-a-Service (IaaS)

– Platform-as-a-Service (PaaS)

– Software-as-a-Service (SaaS).

• A typical high-level architecture of a cloud computing platform consists of : -– Data center.– Provisioning manager.– Monitoring server.– Application server.– Virtualization components.

• These components serve as the back-end of the cloud computing environment.

Let's compare a Dedicated Architecture to a Scalable Cloud Architecture

• Cloud computing can be used in a variety of areas: - – Internal pilots– Hosting virtual worlds– E-business– Social networks– Search.

• It is possible to launch and scale up Web 2.0 applications quickly with cloud architecture.

Cloud computing uses the concept of SLAs (Service Level Agreements) to control, the use and resources, by third parties.

Any SLA management strategy considers two well-differentiated phases:

Negotiation of the contract.

Monitoring of its fulfillment in run-time.

• Users do not own the physical infrastructure.

• They rent usage from a third-party provider.

• They consume resources as a service.

• They pay only for resources that they use.

• Servers are not unnecessarily left idle.

• Users do not have to engineer for peak load limits.

• With increased high-speed bandwidth, response times has been greatly reduced.

• Because cloud computing does not allow users to physically possess the storage of their data such as hard disks.

• It leave the responsibility of data storage and control in the hands of the provider.

• Cloud computing has been criticized for limiting the freedom of users and making them dependent on the provider.

Even if data is securely stored in a cloud, many factors can temporarily disrupt access to the data, such as:-

Network outrages.

Denial of service attacks against the service provider.

Major failure of the service provider infrastructure.

Agility. It improves with users able to rapidly and inexpensively re-provision technological infrastructure resources.

Cost. Is claimed to be greatly reduced and capital expenditure is converted to operational expenditure.

Device and location independence. It enables users to access systems using a web browser regardless of their location or what device they are using (e.g., PC, mobile, etc.).

Reliability. Improves through the use of multiple redundant sites.

Scalability. Through dynamic "on-demand" provisioning of resources.

Security. Typically improves due to centralization of data, increased security-focused resources, etc.

Sustainability. It comes about through improved resource utilization and more efficient systems.

Client Service Application Platform Storage Infrastructure

It consists of computer hardware and software which relies on cloud computing for application delivery.

Cloud Service includes Products, Services and Solutions that are delivered and consumed in real-time over the Internet.

E.g. Web Services “Software Systems designed to support interoperable machine-to-machine interaction over a network“.

Other examples

Identity (OAuth, OpenID)

Integration (Amazon Simple Queue Service)

Payments (Flexible Payment Service, Google Checkout, PayPal)

Mapping (Google Maps, Yahoo! Maps, MapMyIndia)

Search (Alexa, Google Custom Search, Yahoo! BOSS)

Video Games (OnLine)

Live chat (LivePerson)

It leverages the Cloud in software architecture.

It often eliminates the need to install and run the application on the customer's own computer.

It thus alleviates the burden of software maintenance, ongoing operation, and support.

Cloud Platform, such as Platform as a service, is the delivery of a computing platform, and/or solution stack as a service.

It facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers.

Cloud Platform E.g. are: -

Non-Code Based Web Application Framework

WorkXpress

Wolf Frameworks

Cloud Hosting (Rackspace)

Proprietary (Force.com)

Cloud infrastructure, such as Infrastructure as a service, is the delivery of computer infrastructure, typically a platform virtualization environment, as a service.

Full virtualization (Skytap)

Management (RightScale)

Compute (Amazon EC2)

Platform (Force.com)

Storage (Rackspace Cloud Files)

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.

Cloud architecture extends to the client, where web browsers and/or software applications access cloud applications.

Web Service is defined as “A Software System” designed to support interoperable machine-to-machine interaction over a network.

Web services are frequently just Internet Application Programming Interfaces (API) that can be accessed over a network, such as the Internet, and executed on a remote system hosting the requested services.

A cloud computing service provider owns and operates live cloud computing systems to deliver service to third parties.

This requires significant resources and expertise in building and managing next-generation data centers.

The barrier to entry is also significantly higher with capital expenditure required and billing and management creates some overhead.

Significant operational efficiency and agility advantages can be realised, even by small organisations, and server consolidation and virtualization rollouts are already well underway.

A user is a consumer of cloud computing.

The privacy of users in cloud computing has become of increasing concern.

The rights of users is also an issue, which is being addressed via a community effort to create a bill of rights.

• The Windows® Azure™ Platform (Azure) is an internet-scale cloud services platform hosted in Microsoft data centers.

• It provides an operating system and a set of developer services that can be used individually or together.

• Azure’s flexible and interoperable platform can be used to build new applications to run from the cloud or enhance existing applications with cloud-based capabilities.

• Its open architecture gives developers the choice to build web applications, applications running on connected devices, PCs, Servers, or hybrid solutions offering the best of online and on-premises services.

• Microsoft also offers cloud applications ready for consumption by customers such as Windows Live™, Microsoft Dynamics™, and other Microsoft Online Services for business such as Microsoft Exchange Online and SharePoint® Online.

• The Windows Azure Platform lets developers provide their own unique customer offerings by offering the foundational components of compute, storage, and building block services to author and compose applications in the cloud.

Live Services is a set of building blocks within the Windows Azure Platform for handling user data and application resources.

Live Services provides developers with an easy on-ramp to build rich social applications and experiences, across a range of digital devices that can connect with one of the largest audiences on the Web.

The Windows Azure Platform is designed to help developers easily create applications for the web and connected devices.

The services platform offers the greatest flexibility, choice, and control in reaching users and customers while using existing skills.

Millions of developers worldwide already use the .NET Framework and the Visual Studio development environment.

Utilize those same skills to create cloud-enabled applications that can be written, tested, and deployed all from Visual Studio.

In the near future developers will be able to deploy applications written on Ruby on Rails and Python as well.

• The Windows Azure Platform offers a range of businesses flexibility, control, and an affordable solution for running Web-scale applications.

• The services reduce tedious and expensive infrastructure management and planning and are built with security and reliability in mind, along with the option of a pay-as-you-go model.

• Whether you’re a software vendor, corporate IT group, or a start-up, by using the services platform you can focus on your business and the needs of your customers.

What is Cloud Computing?

dhansar@hotmail.com

http://en.wikipedia.org/wiki/Cloud_computing http://www.microsoft.com/azure/default.mspx