Cloud Computing: As easy as 5, 4,3!
Published on by Natasha McAuley
This blog post will explain what cloud computing is through its five characteristics, four deployment models and three service models.
Cloud computing bring us a step closer to computing as an utility. I has transformed how hardware is bought and designed. (Armburst, Fox, Griffith, Joseph, Katz, Konwinski, Lee, Patterson, Rabkin,Stoica & Matei Zaharia, 2010)Cloud computing can be access from anywhere with an internet connection, being used for storage and sharing files. The definition of cloud computing from N.I.S.T. is:
“Cloud computing is a model enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction” (Mell & Grance, 2011).
5 Characteristics of Cloud Computing
The five characteristics that cloud computing have are the broad network access, elasticity, measured service, on-demand self-service and resource pooling.
- Broad Networks
The broad network access means the cloud is available on the internet. This means that it can be used through mobile phones, laptops, desktops and tablets. This also means that there is more flexibility for people to be able to work from different places not needing to go to a certain place, i.e. working at home.
The elasticity means that the provider can scale inward and outward to reach the demand needed by consumers. This makes it appear like that it is unlimited and be able to reach any quantity at any time. For example, if there are a number of consumers who want to use the services of the cloud at once, this should be detected and more servers are available and if less want to use it, there should be less servers.
- Measured Service
Measured service means that the consumers only pay for the amount they are using, whether by user or by a rate per hour. This can be done for services based on active account users, bandwidth, processing and storage. This means that the consumer is only paying for what they use and that the application usage can be monitored and controlled. It also shows a transparency for the consumer and provider of how the application is being utilised.
- On-demand Self-service
On-demand self-service means that “a consumer can unilaterally provision computing capabilities” (Mell & Grance, 2011) as they need it with no human interaction with the server provider is needed, i.e. network storage and connectivity.
- Resource Pooling
Resource pooling is when the cloud provider pools all of their computingresources together. The resources can then be used to serve multiple customers, through using a multi-tenant model. This means that according to the consumer demand, physical and virtual resources can be dynamically allocated and reallocated. Some examples of the resources that can be pooled are memory, network bandwidth, processing and storage.
4 Deployment Models
There are four types of cloud computing private, public, community and hybrid.
- Private Cloud
The private cloud can be run, owned and managed by an organisation, a third party or a combination. The cloud can exist on and off the premises. The cloud infrastructure is meant to be used exclusively by a single organisation with a number of consumers. An example of a private cloud is Amazon Web Services.
- Public Cloud
The public cloud can be run, owned and managed by a business, an academic organisation, a government organisation or a combination. The cloud can exist on and off premises. The cloud is meant for general public to use through self-service. An example of a public cloud is Windows Azure Services Platform.
- Community Cloud
The community cloud can be run, owned and managed by one or more of the organisations in the community, a third party or a combination. The cloud can exist on and off premises. The cloud infrastructure is meant to be used specifically by a community of organisations that have common concerns. This mean that there is less cost for each organisation than if they were using a public cloud. An example of a community cloud is a cloud within the healthcare system.
- Hybrid Cloud
The hybrid cloud is a conformation of two or more distinct cloud infrastructures (private, public and community). The clouds remain unique entities but are bound together by “standardised or proprietary technology that enabled data and application portability” (Mell & Grance, 2011). This means that the organisation will get the benefits from the different models. An example of a hybrid cloud is Amazon Simple Storage Service.
3 Service Models
There are three broad-service categories, Software as a Service (SaaS), Platform as a service (PaaS) and Infrastructure as a Service (IaaS).
- Software as a Service (SaaS)
SaaS is a model where the application provided is running on cloud infrastructure. They are accessible from different interfaces and devices, such as on a desktop or a mobile device. The consumer doesn’t control or manage the any of the underlying cloud infrastructure, such as the servers and network, storage and application capabilities, except the “limited user-specific application configuration settings” (Mell & Grance, 2011). An example of the SaaS model is Microsoft Office 365.
- Platform as a service (PaaS)
PaaS is a model where the consumer is able to deploy onto the consumer-created cloud infrastructure. They acquire applications created using programming supported by the provider. However, the consumer cannot control or manage the underlying cloud infrastructure, but does have “control over the deployed applications and possibly the configuration settings for the application-hosting environment” (Mell & Grance, 2011). An example of the PaaS model is Salesforce.com.
- Infrastructure as a Service (IaaS)
IaaS is a model where the consumer is able to rent the storage, networks and other fundamental computational resources from the cloud provider. The consumer can deploy and run arbitrary software, such as operating systems and applications. However, the consumer cannot control or manage the underlying cloud infrastructure, but does have “control over the operating systems storage and deployed applications” (Mell & Grance, 2011). An example of the IaaS model is Amazon Web Services.
As you can see cloud computing is easy to understand with just 5, 4, 3.
- Armbrust, M., Fox, A., Griffith, R., Joseph, A.D., Katz, R., Konwinski, A., Lee, G., Patterson, D., Rabkin, A., Stoica, I., &Zaharia, M., 2010,Communications of the ACM. Apr2010, Vol. 53 Issue 4, p.50-58.
- Mell, P. & Grance, T., 2011, The NIST Definition of Cloud Computing, National Institute of Standards and Technology, U.S. Department of Commerce