Want to have some idea about Cloud computing?
Here are some of the main characteristics
Cloud computing has distinct characteristics which differentiates it from its counter parts. Mell and Grance define them as follows.
- Self service which is available on demand. Clients can demand them whenever they need the services and pay for them accordingly.
- Pooling of resources: Providers combine resources using strategies like virtualization and multitenancy. In this way, they serve multiple consumers.
- Rapid elasticity: The cloud computing is flexible as consumers can increase or decrease resources depending on their needs. They can also change the duration of their tasks.
- Pay and Use service: The biggest advantage is that you need not subscribe for a cloud computing service. That means no initial financial investment. Consumers can select either pay by use or pay as you go pricing model.
Cloud service models-an overview
Cloud computing is served through 3 service models.
SaaS (Software as service)
The software providers deliver software and applications on demand from consumers through the internet. The facility is available on subscription basis, or free. Using SaaS , consumers can reduce their maintenance costs ,fares associated with redundancy, upgrades. Some of the popular SaaS are Facebook, Twitter, Google Apps, Drop box etc.
Do not mistake it as Paas. It is actually platform as service. Here the virtualized tools act as platform and provide service to users. The tools may come in various forms on which the applications work. The tools are in the form of operating systems, virtual machines, development environments, and several other applications (30).Using Paas, the users can develop, deploy or host complex applications using several computer languages. Some of the common examples of PaaS are Google App engine, Amazon EC2 map reduce etc.
Infrastructure as Service (IaaS)
The name itself is suggestive of the function. The IaaS provides materials and support required for services in Infrastructure (27).H ere the provider owns the infrastructure, but the user has control over the infrastructure services. The provider houses and maintains the infrastructure. Some of the popular examples of Iaas are Amazon web services, Eucalyptus, Rackspace cloud, etc.
Other service models
XaaS(everything as a service). Cloud computing is also popularly known as Xaas too. Bose proposes X-a as a service. Lenk et al (33), Cloud service alliance(23)and Leimeiter et al also used a new model Human as service (Huaas), Security as Service (se-caa-as )and Communication as a service as examples of X-a as in different instances.
Clouds as deployment models
Some of the cloud deployment models are Private, Public, Hybrid or Community
The cloud platform is available for the use of general public through internet for open use.
The provider runs the model on its premises. Usually businesses and large scale industries prefer this model. Advantages are cost efficiency, flexibility, resilience and easy management. The cons are security deficiencies in the form of malicious attacks and easy access.
Operated solely by organizations, the private clouds may comprise of many units. The private cloud is maintained by the IT department of the organization. Sometimes the service is done by external provider too. The private cloud usually does not have network bandwidth constraints, legal requirements and security exposures. Special features are the ability to host customer services according to customer specifications.
A shared infrastructure usually used managed by a provider among several organizations is the community cloud. As it is shared by several organizations, the main concern is security and compliance. The model is used by governmental agencies, educational companies, and health care professionals.
The name itself suggests that the cloud platform is a hybrid of two. Here the partners are bundled together, but each of them works separately. The hybrid cloud in turn tries to improve the weak points in the combination of clouds. Hybrid clouds are used in organizations where large amount of confidential data has to be stored and managed. The confidential data is stored on the private cloud while the general process is done through the public cloud.
Definition of SME’s
SME is defined by the National Small business act as follows: Three parameters are used for defining SME. Number of employees, turn over and gross assets. The act defines SME as a small enterprise with smaller number of employees up to 50 and medium enterprise with employees in between 100 and 200.