Cloud computing

In Computer science, cloud computing describes a type of outsourcing of computer services, similar to the way in which electricity supply is outsourced. Users can simply use it. They do not need to worry where the electricity is from, how it is made, or transported. Every month, they pay for what they consumed.

The idea behind cloud computing is similar: The user can simply use storage, computing power, or specially crafted development environments, without having to worry how these work internally. Cloud computing is usually Internet-based computing. The cloud is a metaphor for the Internet based on how the internet is described in computer network diagrams; which means it is an abstraction hiding the complex infrastructure of the internet. It is a style of computing in which IT-related capabilities are provided “as a service”, allowing users to access technology-enabled services from the Internet ("in the cloud")without knowledge of, or control over the technologies behind these servers.

According to a paper published by IEEE Internet Computing in 2008 "Cloud Computing is a paradigm in which information is permanently stored in servers on the Internet and cached temporarily on clients that include computers, laptops, handhelds, sensors, etc."

Cloud computing is a general concept that utilizes software as a service (SaaS), such as Web 2.0 and other technology trends, all of which depend on the Internet for satisfying users' needs. For example, Google Apps provides common business applications online that are accessed from a web browser, while the software and data are stored on the Internet servers.

Components

Application

A cloud application influences The Cloud model of software architecture, often eliminating the need to install and run the application on the customer's own computer, thus reducing software maintenance, ongoing operations, and support. For example:

• Peer-to-peer/volunteer computing (Bit torrent, SETI@home, Skype)
• Web application (Face book)
• Software as a service (Google Apps, Sales force)
• Software plus services (Microsoft Online Services)

Client

A cloud client is computer hardware and/or computer software which relies on The Cloud for application delivery, or which is specifically designed for delivery of cloud services, and which is in either case essentially useless without a Cloud. For example:

• Mobile (Android, iPhone, Windows Mobile)
• Thin client (Cherry Pal, ZonbugOS based systems)
• Thick client/Web browser (Google Chrome, Mozilla Firefox)

Infrastructure

Cloud infrastructure (e.g. Infrastructure as a service) is the delivery of computer infrastructure (typically a platform virtualization environment) as a service. For example:

• Full virtualization (GoGrid, Skytap)
• Grid computing (Sun Grid)
• Management (Right Scale)
• Para virtualization (Amazon Elastic Compute Cloud)

Platform

A cloud platform (e.g. Platform as a service) (the delivery of a computing platform and/or solution stack as a service) facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers. For example:

• Web application frameworks
• Python Django (Google App Engine)
• Ruby on Rails (Heroku)
• Web hosting (Mosso)
• Proprietary (Azure, Force.com)

Service

A cloud service (e.g. Web Service) is "software system[s] designed to support interoperable machine-to-machine interaction over a network"which may be accessed by other cloud computing components, software (e.g. Software plus services) or end users directly. For example:

• Identity (OAuth, OpenID)
• Integration (Amazon Simple Queue Service)
• Mapping (Google Maps, Yahoo! Maps)
• Payments (Amazon Flexible Payments Service, Google Checkout, PayPal)
• Search (Alexa, Google Custom Search, Yahoo! BOSS)
• Others (Amazon Mechanical Turk)

Storage

Cloud storage is the delivery of data storage as a service (including database-like services), often billed on a utility computing basis (e.g. per gigabyte per month). For example:

• Database (Amazon SimpleDB, Google App Engine's Big Table data store)
• Network attached storage (Mobile Me iDisk component, Nirvana CloudNAS)
• Synchronization (Live Mesh Live Desktop component, Mobile Me push functions)
• Web service (Amazon Simple Storage Service, Nirvanix SDN)

Traditional storage vendors have recently begun to offer their own flavor of cloud storage, sometimes in conjunction with their existing software products (e.g. Symantec's Online Storage for Backup Exec). Others focus on providing a new kind of back-end storage optimally designed for delivering cloud storage (EMC's Atoms), categorically known as Cloud Optimized Storage

Roles

Provider

A cloud computing provider or cloud computing service provider owns and operates cloud computing systems serve someone else. Usually this needs building and managing new data centers. Some organizations get some of the benefits of cloud computing by becoming "internal" cloud providers and servicing themselves, though they do not benefit from the same economies of scale and still have to engineer for peak loads. The barrier to entry is also significantly higher with capital expenditure required and billing and management creates some overhead. However, significant operational efficiency and quickness advantages can be achieved even by small organizations, and server consolidation and virtualization rollouts are already in progress. Amazon.com was the first such provider, modernizing its data centers which, like most computer networks were using as little as 10% of its capacity at any one time just to leave room for occasional spikes. This allowed small, fast-moving groups to add new features faster and easier, and they went on to open it up to outsiders as Amazon Web Services in 2002 on a utility computing basis.

The author of this article is Assistant Professor, Pioneer Institute, Indore