Cloud Computing Introduction and Characteristics
Before describing the NIST cloud computing model and the different ways that clouds are used let’s address the question that why there is the so much excitement about cloud computing?
The value proposition of cloud computing is that it allows computer users also referred to as customers or consumers to conveniently wren access to applications, software development and deployment environments and computing infrastructures such as data storage and processing. This potential can be of cost effective solutions to those consumer organizations that might not have the capital to purchase large enterprise software solutions or setup large computing hardware and software infrastructure.
The value proposition is also compelling to software, Hardware and system vendors to now have alternatives to selling relatively expensive products to smaller and possibly more conscious customers. It is ben predicted that new products and services created by cloud computing could produce 1.1 trillion a year in new business revenues from 2011 to 2015 and spending on public and private cloud and it services will generate nearly 14 million jobs worldwide. According to a 2010 study the analysis firm IDC.
There is nothing particularly new about the concept underlying cloud computing. Programming language innovator and computing pioneer john mccarthy introduced the model of shared virtualized resources that he called utility computing in a 1961 presentation. Through the 1960s and 70s large banks of computers provide so called time sharing services to local and remote users in 1980 and early 19s large distributed datacenters became common place in large corporation and through the early release until today internet enabled software as services models and virtualization of resources continues to be improved and rebranded today we call these services cloud computing.
While the concept of cloud computing is not new. What is new however is that faster data communications capability, faster and more reliable computing power denser and cheaper storage and new programming paradigms have enabled comprehensive computational resource sharing to become vast pervasive and economical since cloud computing is simply a manifestation of natural evaluation of computational resource sharing over many decades however we can characterize in a way that differentiate it from simple networking.
The following dive characteristics are useful in distinguishing the cloud computing.
That is a consumer can unilaterally provision computing capabilities such as server time and network storage as needed without requiring human interaction with the service provider.
Broad Network access:
Here capabilities are available through standard mechanism that promote use by different thin or thick client platforms such as mobile phones, tablets, laptops and workstations.
That is the provider’s computing resources are comingle to serve multiple consumers using a multi-tenant model with different physical and virtual resources dynamically assigned and reassigned according to user demand. There is a sense of location independence in that the consumer generally have no control or knowledge over the exact location of the provided resource. Bot may be able to specify location at a higher level of abstention, country, state or data center. Example of such a resource include CUP data storage, memory capacity and network bandwidth rapid elasticity here capabilities can be reconfigured in some cases automatically to scale rapidly outward, inward in response to changing demands. To the consumers the capabilities available to provisioning often impaired to be unlimited and can be acquired at any time.
This characteristic refers to the ability of the cloud systems to automatically control and optimize resource utilization through monitoring, measurement and reporting them to cloud attributes. For example, storage capacity, processing power, network bandwidth and number of active user accounts. There are three essential service models for cloud computing.
Software as a service:
In software as a service the capability provided to the consumers is to use the provider’s application running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser or a program interface. The consumer doesn’t control or manage the cloud infrastructure such as network, servers, operating systems, storage or even individual application capabilities with the possible exception of limited user related application configuration settings. Web based email, sales source and online sales management are examples of software as service.
Platform as a service:
With platform as a service consumer deploys consumer created or acquires applications on to the cloud infrastructure using programming languages and tools provided by the provider. The consumer doesn’t manage or control the underlying cloud infrastructure such as network, servers, operating systems or storage but have control over the deployed application and possibly the application hosting environment configurations. Google provide this type of service where users develop and host web applications using Google’s development tools.
Infrastructure as a service:
Finally, with the infrastructure as a service the consumer is able to access the processing, storage networks and other fundamental computing resources. The consumer doesn’t manage or control the underlying cloud infrastructure but have control over operating system, storage deployed applications and limited control over certain networking components such as host firewalls. Amazon providers this type of service where users can rent virtual servers on which they run their own applications.