After all, what is cloud computing? And what it is not? The concept of cloud computing still generates some controversy. Since the advent of the Internet, there were several suppliers who have been offering hosting services and created Data Center which absorbed a significant part of the park equipment that once stood within companies.
When it came into play, and the concept was not clear, the cloud computing was characterized in a very comprehensive way, including any form of server virtualization and outsourcing of computing infrastructure. Thus, for some time, the term took on a general nature and did not characterized a working model clearly in order to identify their specific attributes and benefits. But, as the solutions offered by the market were consolidated, definition of proposals have emerged for the concept of cloud computing.
Cloud Computing Concept
Among the various definitions proposed, one that has been widely accepted by the market and is increasingly cited in the literature is that proposed by NIST, the National Institute of Standards and Technology of the US Department of Commerce , in 2011:
“Cloud services in India is a model for enabling ubiquitous access, convenient and under network via demand to a shared pool and configurable computing resources (eg, networks, servers, storage devices, applications and services) that can be provided quickly and released with minimal management effort or interaction with the service provider.”
Essential Characteristics of Cloud Model
Also in the text that presents the definition of NIST, have listed five essential characteristics of cloud computing model :
1) Self-DEMAND: The consumer must be able to allocate new resources automatically, without human interaction with the service provider;
2) ACCESS NETWORK VIA WEB: Resources must be available over the network and must be available by default mechanisms, allowing its use for different devices such as personal computers, smartphones , tablets , etc;
3) GROUPING RESOURCES: The computational resources of the service provider should be grouped to serve multiple consumers with physical and virtual resources being arranged and rearranged dynamically as per the demand for these consumers. There must be a sense of location independence, in which the consumer does not have an accurate track of where the resources used are located, but it should be possible to specify that location in high abstraction level (country, federal unit or data center );
4) GIVE FAST: Resources should be allocated and released elastically, and in some cases automatically, allowing for quick adaptation to demand. For the consumer, the resources available should appear to be unlimited, and you can allocate the desired amount of these resources at any time;
5) MEASURED SERVICES: Cloud computing services must monitor and optimize the resources automatically, providing mechanisms to measure these features using an appropriate measurement system for the type of resource being used (eg, amount of storage space, speed communication, processing capacity, number of active users, etc.). It should be possible to monitor, control and query the use of resources, providing transparency for the consumer and the provider of services.
According to NIST, Cloud Computer Service does not require “to order” new servers;
Does not require the contract to supply services to be changed whenever you wish to change the available computing resources – adding or removing servers or increased disk space, for example;
Allows resources to be allocated, deallocated or reconfigured on demand.
For example, a cloud computing service that meets the definition proposed by NIST should provide automatic mechanisms for dynamic allocation of new servers based on rules for using the computing capacity in use, something like an automatic rule of the “allocate a new server whenever the current set of servers reaches to 80% of its maximum processing capacity”.
Similarly, the ideal is that the services offered by the computational model cloud computing are unlimited, as in the case of disk storage services, and it is not necessary to “pre-allocate” a certain amount of these resources. The same applies to the transmission band and reception of data via the Internet.
Therefore, when selecting a provider of cloud computing services, you get assess, based on these fundamental characteristics proposed by NIST, the degree of compliance of the services offered by it to the fundamental model of cloud computing. For some providers, you may be shocked to discover that they did not even know how to conceptualize or what is cloud computing.
Finally, NIST itself points out that the concept of cloud computing is evolving.
The definition they proposes is not definitive, therefore, may also evolve in the upcoming time.