Coud computing safety

Cloud computing is a networked computer hosting service first introduced by Amazon with its Amazon Web Services (AWS) offering in 2006. At the time, Amazon's aim was to commercialize the unused computing power of servers deployed around the world for its own use, and which were only being used at 10% capacity, in order to cope with seasonal peaks, particularly during the holiday season.

The idea of an IT service offering detached, thanks to the network, from the technical characteristics of its implementation had been formulated a few years earlier, for example by researchers such as Michel Volle .

The originality of cloud computing compared to traditional data hosting, website hosting or compute server hosting is based on the following five characteristics:

• deploy and stop services on demand, in self-service, generally via a web interface, almost instantaneously ;

• high-speed network access ;

• pooling of non-localized resources: infrastructure, network, software, storage, etc;

• rapid allocation and deallocation of resources ("elasticity");

• billing based on consumption, typically on an hour-by-hour basis.

This flexibility is made possible by the availability of four technologies that are already well known, but whose performance has recently made considerable progress: distributed computing, a ubiquitous high-speed network, the Domain Name System (DNS), and efficient platforms for virtual machines. A few remarks on these technologies:

• the need for a fast, ubiquitous network is obvious;

• the availability of efficient virtualization systems, analyzed in detail in this article. It enables new servers to be easily, and in some cases automatically, deployed on demand, whereas if they were physical machines, a whole logistics chain of transport, power distribution and network infrastructure would be required;

• the use of advanced DNS management techniques gives this distribution in space (physical and topological) the necessary...