Cloud Computing Model, Benefits and Disadvantages
The NIST SP 800-145 states that cloud computing is a model for “enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources”. These resources include networks, servers, storage, applications, and services that can be quickly configured and deployed with minimal management or service provider actions. The cloud model consists of five characteristics, three service models, and four deployment models (Grance, & Mell, 2011, pg.2).
Cloud computing characteristics as follows (Grance, & Mell, 2011, pg.2):
- On-demand self-service.
- Broad network access.
- Resource pooling.
- Rapid elasticity.
- Measured service.
Cloud service models as follows:
- Software as a Service (SaaS) which are web-based applications accessible by client devices such as web browsers. With the SaaS model the consumer does not manage or control the underlying cloud infrastructure hardware or Operating System (OS), storage, or many of the individual application capabilities (Grance, & Mell, 2011, pg.2). The application SalesForce is an example of SaaS where the client has access to just the application but none of the underlying infrastructure or settings (SalesForce SaaS, n.d.).
- Platform as a Service (PaaS) is a cloud model where the consumer does not manage or control the underlying cloud infrastructure such as hardware, OS, and network devices, but has control over its deployed applications and many configuration settings for application-hosting (Grance, & Mell, 2011, pg.2-3). Paasify.it vendors (n.d.) provides a comparison list of many reputable PaaS vendors.
- Infrastructure as a Service (IaaS) is a model where the consumer does not manage or control the underlying cloud infrastructure, but does have control over operating systems, storage, and deployed applications (Grance, & Mell, 2011, pg.3). Amazon EC2 is a well-known cloud service that provides virtual environments which allow customers control over software, storage, and configurations (Amazon EC2, n.d.).
Cloud deployment models as follows (Grance, & Mell, 2011, pg.3).
- Private cloud where the cloud infrastructure is provisioned for exclusive use by a single organization.
- Community cloud where cloud infrastructure is provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns.
- Public cloud where cloud infrastructure is provisioned for public use.
- Hybrid cloud where the cloud infrastructure is a composition of two or more other cloud infrastructures.
The advantages of cloud computing include the following (Levelclound.net, n.d.):
- Cost savings. Cloud computing allows an organization access to computing resources they may not be able to afford otherwise. Additionally, with cloud computing, organizations do not have to invest in infrastructure like data centers. Cloud models allow companies to pay only for resources they use.
- Cloud providers maintain large data centers with extensive failover. Additionally, most cloud providers offer Service Level Agreements (SLA) that guarantee high-availability among other guarantees.
- Cloud vendors usually provide management tools which simplify managing applications and infrastructure settings.
- Competitive edge. Cloud computing allows smaller organization access to computing resources they may not be able to afford otherwise. This allows these organizations to compete better against organizations that are much larger.
The disadvantages of cloud computing include the following (Levelcloud.net, n.d.):
- Even though cloud providers offer high-availability it is still possible to overwhelm provider resources. The other aspect of downtime to consider is connectivity. Access to cloud services and applications require remote access, usually through an internet provider. If the internet provider goes down the organization loses access to cloud resources.
- Even though most established reputable cloud providers implement high security standards, there are additional risks to data stored on a cloud. The risk increases if the cloud resource is shared or on a publicly accessible cloud.
- Vendor lock-in. Many cloud vendors require contracts that can sometimes make it difficult to switch providers. This issue puts more emphasis on clearly understanding the expectations documented in vendor contracts and Service Level Agreements (SLA)’s.
Amazon EC2. (n.d.). Elastic Computer Cloud. Retrieved June 28, 2016, from https://aws.amazon.com/ec2/.
Grance, T., & Mell, P. (2011, September). The NIST Definition of Cloud Computing, NIST SP 800-145. Retrieved June 28, 2016, from http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-145.pdf.
Levelcloud.net. (n.d.). Advantages and Disadvantages of Cloud Computing. Retrieved June 28, 2016, from http://www.levelcloud.net/why-levelcloud/cloud-education-center/advantages-and-disadvantages-of-cloud-computing/.
Paasify.it, vendors. (n.d.). Find Your Platform as a Service. Retrieved June 28, 2016, from https://paasify.it/vendors.
SalesForce SaaS. (n.d.). SaaS: Software as a Service. Retrieved June 28, 2016, from https://www.salesforce.com/saas/.