Cloud Computing - Overview, layers, usages and benefits

Résumé du document

What is cloud computing? The main idea of this new concept of the computer science, is that you can get the power you need whenever you want. How can it be possible? In fact, cloud computing is a new paradigm of computing infrastructure. But what is so incredible in cloud computing to qualify it as a new paradigm? The major revolution is that the infrastructures are moved to the network. Indeed, thanks to internet, you can get the power of many machines around the world without owning them ! So, as you can guess, cloud computing is a major evolution in computer science, or, all the least, it is considered as a major evolution. Amazon was the first firm to propose a cloud computing offer with EC2 in 2006.

Now, you have a small idea of what is cloud computing, but what is the formal definition?
Unfortunately, the variety of technologies makes the overall picture confusing. Many experts in computer science have their own definition of what is the cloud. Here is two of those. The first one is due to Markus Klems, a research assistant at the Germany-based FZI Research Center for Information Technology. He is meant to be specialized in cloud computing. His definition is that immediate scalability and resources usage optimization are key elements for the cloud computing.

The second definition is due to Paul McFredies, a Canadian author of more than 60 computer books. As a book writer, he is used to define concepts in order to make them understandable by everyone. For him, Data centers are the basic units of the Cloud, offering huge amounts of computing power and storage thanks to spared resources. And finally, the third one is virtualization because the complexity of the infrastructure and the physical location of the resources are hidden from the user.

We have decided to propose another definition which is a mix of many definitions. This proper definition has been established by the NIST (the National Institute of Standards and Technology), an agency of the U.S. Department of Commerce: Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable resources (networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

Instead of memorizing this long definitions, you just have to remember the key words associated with cloud computing. The first one is scalability, because you get the exact amount of power you need, the second one is, pay per use, because as those words suggest, you pay for your usage. And finally, the third one is virtualization, because, the infrastructures are stored in data centers, and you have access to their capacities using internet and software.