04/12/2017
Cloud Computing
Introduction
What really is cloud computing?
We will be explaining in simple but concise way what cloud computing is all about, history, it's advantages and also disadvantages.
Definition
Cloud Computing is a buzzword of 2010 and many experts disagree on its exact definition. But the most used one and concurred one includes the notion of web‐based services which are available on demand from and optimized and highly scalable service provider. Since such a disagreement on the definition, one will be provided to better understand of the notion. The cloud is IT as a service, delivered by IT resources that are independent of location. It is a style of computing in which dynamically scalable and often virtualized resources are provided as a service over the Internet where end‐users have no knowledge of, expertise in, or control over the technology infrastructure (the cloud) that supports them.
Attributes
Before some of the attributes will be defined, the term cloud should be explained. A cloud has been long used in IT, in network diagrams respectively, to represent a sort of black box where the interfaces are well known but the internal routing and processing is not visible to the network users. Key attributes in cloud computing:
Service‐Based: Consumer concerns are abstracted from provider concerns through service interfaces that are well‐defined. The interfaces hide the implementation details and enable a completely automated response by the service provider. The service could be considered "ready to use" or "off the shelf" because it is designed to serve the specific needs of a set of consumers, and the technologies are tailored to that need rather than the service being tailored to how the technology works. The articulation of the service feature is based on service levels and IT outcomes such as availability, response time, performance versus price, and clear and predefined operational processes, rather than technology and its capabilities. In other words, what the service needs to do is more important than how the technologies are used to implement the solution.
Scalable and Elastic: The service can scale capacity up or down as the consumer demands at the speed of full automation (from seconds for some services to hours for others). Elasticity is a trait of shared pools of resources. Scalability is a feature of the underlying infrastructure and software platforms. Elasticity is associated with not only scale but also an economic model that enables scaling in both directions in an automated fashion. This means that services scale on demand to add or remove resources as needed.
Shared: Services share a pool of resources to build economies of scale and IT resources are used with maximum efficiency. The underlying infrastructure, software or platforms are shared among the consumers of the service (usually unknown to the consumers). This enables unused resources to serve multiple needs for multiple consumers, all working at the same time.
Metered by Use: Services are tracked with usage metrics to enable multiple payment models. The service provider has a usage accounting model for measuring the use of the services, which could then be used to create different pricing plans and models. These may include pay‐as‐you go plans, subscriptions, fixed plans and even free plans. The implied payment plans will be based on usage, not on the cost of the equipment. These plans are based on the amount of the service used by the consumers, which may be in terms of hours, data transfers or other use‐based attributes delivered.
Uses Internet Technologies: The service is delivered using Internet identifiers, formats and protocols, such as URLs, HTTP, IP and representational state transfer Web‐oriented architecture. Many examples of Web technology exist as the foundation for Internet‐based services. Google's Gmail, Amazon.com's book buying, eBay's auctions sharing all exhibit the use of Internet and Web technologies and protocols. More details about examples to come much later.
History
History of Cloud Computing surprisingly began almost 50 years ago. The father of this idea is considered to be John McCarthy, a professor at MIT University in US, who first in 1961 presented the idea of sharing the same computer technology as being the same as for example sharing electricity. Electrical power needs many households/firms that possess a variety of electrical appliances but do not possess power plant. One power plant serves many customers and using the electricity example, power plant=service provider, distribution network=internet and the households/firms=computers.
Since that time, Cloud computing has evolved through a number of phases which include grid and utility computing, application service provision (ASP), and Software as a Service (SaaS). One of the first milestones was the arrival of Salesforce.com in 1999, which pioneered the concept of delivering enterprise applications via a simple website. The next development was Amazon Web Services in 2002, which provided a suite of cloud‐based services including storage, computation and even human intelligence. Another big milestone came in 2009 as Google and others started to offer browser‐based enterprise applications, though services such as Google Apps.
.... To be continued.
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