Cloud computing model that supports convenient, on-demand software access via network access to a shared group of configurable computing devices (e.g., servers, networks, applications, services and storage) that can be released and fast provisioned with less management work and service provider interaction.
The model for cloud computing supports the availability and comprises of five required characteristics, four deployment and three service structures.
Necessary Characteristics
On-demand self-service:
Any customers can unilaterally running computing capabilities, like network storage and server time, as desirable automatically without involvement of human interaction with every provider of service.
Broad network access:
Services are there over network and it can be accessed over standard mechanisms which promote use by mixed thick or thin user platforms (e.g., handheld devices such as mobile phones and others such as laptops, and PDAs).
Resource pooling:
Resources of provider are grouped to serve number of users by means of a multi-tenant structure along with different virtual and physical resources assigned dynamically. There is some kind of sense of location freedom in that the consumer usually has no knowledge or control over the precise place of provided services but is able to specify location at higher abstraction level (e.g. continent, country, state and/or data-center).
Rapid elasticity:
Services can be elastically and rapidly running, in many cases automatically, to speedily scale out and fast released to rapidly scale in. To customer, the services available for running often appear to be unlimited that can be bought in any amount at any instant of time.
Measured Service:
In cloud system resources are automatically controlled and optimized and it is done by controlling a metering at some level of abstraction suitable to the kind of service (example bandwidth, processing, storage, and accounts of active users).
Service Models
Cloud Software as a Service:
Capabilities provided to the customer is to use application running on the infrastructure of service provider. The applications are easily accessible from several client devices via thin client interface like web browser that may be web email. Here customer does not control or manage the cloud infrastructure that includes network, server, operating systems, storage, memory or even single application with the possible allowance of user-specific application setting and configuration.
Cloud Platform as a Service:
The service given to the user is to install on the infrastructure of cloud system created by user itself or acquired application that may be written in some programming language and using tools that are supported and/or provided by the services provider. The end user does not control or manage the infrastructure of cloud computing system that comprises servers, networks storage, or operating systems. But the end user can control the installed applications and available hosting environment configuration.
Cloud Infrastructure as a Service:
In this same capabilities and resources are provided but consumer can deploy and run software. The user does not control infrastructure.
Deployment Models
Private cloud:
This cloud infrastructure is functioned only for an organization.
Community cloud:
This cloud infrastructure is common to several organizations.
Public cloud:
This cloud infrastructure is available to public or large industry group.
Hybrid cloud:
It is composite of two and more than two clouds.
Key characteristic and features of Cloud Computing
There is no general standard definition provided to the cloud computing mechanism. There might be some more time required to define properly the features of the cloud computing mechanism. There can be two basic technologies that are said to play an important role in the whole mechanism of the cloud computing. They are described as follows:
Virtualization technology
The technology of the virtualization is seen to work upon the handling of the functioning of how the whole images of our operating system along with the middle-ware as well as the applications all stack away. This technology might also be further used so as to help reuse the licenses of the given operating systems and the middle-ware or any other software application programs.
Service oriented architecture
The service oriented architecture of the cloud computing mechanism is said to be a large collection of various services. All these services present in the architecture together function and communicate well with each other. This process of communication among the services of the cloud computing architecture is seen to involve normal passing of data. Besides this it might also involve more than two services that are into the coordination of some of the activities. For all this it is seen that there is some means of connection among these services that is required to make them be together to function properly. The software architecture of the cloud computing system is getting more service oriented unlike the others. Not majority of the applications are seen to be operating as standalone applications.
With the recent boom in the growth of the internet technology among the people all over the world it has been seen that the whole use of this software mechanism can easily now be rented. Huge successful companies like the Google, Sun or even the Microsoft are seen to now have this ability with which they can provide all the good services related to the software. This does not involve the selling of the software. The cloud computing architecture mechanism is seen to address the re-usability, flexibility and componentization all together. All these mentioned features are in great need by various companies especially the ones that are looking out for a decreased cost and are opting for the rental mechanism instead of going for the purchase of the software.
Cloud computing and its relation to economics of scale
One thing that is seen under the cloud computing mechanism is that the whole process is upon some group of resources constructed solely for sale purposes and that the resources used in it are from the basic IT network background. By mentioning the word cloud it should be understood that it includes an attempt so as to construct the scales. Hence many clouds are based on this scalability factor. A large number of customers will hence definitely prove to be good in the end as it would give a great advantage in terms of the cost. Hence all such factors have to be kept in mind for cloud computing and its relation to the scalability.
