This deployment model is rather confusing because it is neither entirely public nor entirely private and yet it’s not hybrid either. It is a type of cloud that is provisioned from a cloud service provider that offers an entirely dedicated cloud environment to a client, one that’s separate from and not shared with other semi-private cloud customers. In short, it is a non- multitenant cloud service offered by a public cloud service provider that is delivered over pub- lic channels but contains all of the characteristics of a private cloud (including security and control) but is still considered to be off-premises. A dedicated server is a common example of a semi-private cloud that runs entirely for a single customer. It is not part of a public cloud environment, is accessed over a secure VPN or web connection, and provides enhanced levels of control of the cloud environment at the customer’s side. Organizations looking to leverage the power of a secure and exclusive cloud in a cost-effective way are well suited for this type of cloud deployment model.
The following types of organizations are suited for a semi-private cloud deployment:
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■ Application developers (mobile/web/SaaS) that can utilize a dedicated server to develop, test, and deploy applications and services
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■ Banks that deploy and deliver external or partner banking applications through an external cloud
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■ E-commerce stores and web portals hosted and managed within a private cloud envi- ronment located on a provider’s premises
Another, similar deployment is co-location, where the customer deploys and houses servers and other computing resources within the cloud service facility of a provider. The service provider maintains, manages, and operates the servers on the customer’s behalf and delivers a cloud environment that can be accessed from anywhere over the public Internet.
This is a good fit for organizations that are looking for a private cloud solution but have no means of housing a hardware infrastructure and do not want on-premises IT staff and other resources to operate the cloud environment.
Public
The public cloud deployment model is the most widely used and popular deployment model for cloud solutions. It is considered the true form of cloud computing or hosting. Public cloud environments are entirely owned, deployed, monitored, and managed by the cloud service provider. Public cloud customers can generally be any organization or entity that has some computing requirements. The customers can create and access cloud resources such as stor- age, computing, and software on a metered, pay-as-you-go billing scheme, and they can source virtual servers (from a single virtual server to thousands), cloud storage components, applications, and other resources instantly through a process called provisioning. The sell- ing point for public cloud offerings is that customers do not need to spend much on up front capital costs, nor do they have to relinquish ongoing operational costs in order to create, access, and manage such resources. The cloud computing facility is shared by multiple users simultaneously. They each have their own share of computing resources, and their data and processes may intermingle in what appears to be separate machines with other customers’
data and processes without them knowing it. This is called virtualization, which means that multiple customers are sharing or utilizing the same set of resources.
The following types of organizations are suited for the public cloud deployment model:
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■ General businesses (small and medium enterprises, or SMEs) using a public cloud to host their applications, back up data and files, and more
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■ Software developers and publishers that deliver their software on a Software as a Service (SaaS) platform
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■ IT service providers, managed service providers (MSPs), and value-added resellers (VARs) that use a public cloud to deliver IT solutions and services
Hybrid
The hybrid cloud deployment model enables organizations to keep their data secure and under their control in an on-premises or private cloud environment while also provisioning applications and shared storage from the public cloud. It is a combination of two or more cloud deployment models—specifically, using a private and public cloud. The hybrid cloud model is ideal for organizations that have some reservations about using the cloud but are still interested in gaining its benefits.
The following types of organizations are suited for a hybrid cloud deployment:
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■ SMEs having multiple IT resource requirements and using a public cloud to balance traffic/computational load from private to public cloud
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■ IT service providers using a combination of private and public cloud models to service their clients
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■ Application/software developers using a public cloud for testing, integration, and deployment
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Community
A community cloud is a type of cloud computing deployment model that is used between a selective group of users or organizations. A community cloud is generally provisioned using public cloud technologies, but it can also be delivered using the private or even the hybrid model. The community cloud can consist of a number of individuals or organizations working on a joint project and/or collaborating knowledge and data among each other.
The following types of organizations are suited for the community cloud model:
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■ Scientific research organizations that use the community cloud to perform work on joint projects, research, and experiments
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■ Government organizations using SaaS application to perform business processes that are deployed and delivered through a community cloud
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■ Educational institutions sharing a community cloud to perform research and/or share knowledge
On-Premises vs . Off-Premises Hosting
The on-premises versus off-premises debate is nothing new. It existed even before the advent of real cloud computing. Way back in the 1961, John McCarthy of artificial intel- ligence (AI) and Lisp fame suggested during a speech given at MIT’s centennial that utility computing would become an ideal business model. Following that notion, in the age of mainframes and large supercomputers, computing was mainly done online through early networking technologies. Companies bought computing time from mainframe providers, and users would sit behind extremely slow terminals for hours imputing data and creating reports. It was very labor intensive and costly. This went on for more than a decade until personal computers became powerful enough, with larger storage capacities and cheaper price points, to allow real on-premises computing. These PCs were still extremely slow and expensive compared to today’s offerings, but they offered more value compared to the all- online utility computing alternative at that time. Remember your PCs from the ’80s? They were essentially as powerful as modern calculators with the price point of high-end work- stations. But at that time, they opened up a whole new world of personal computing possi- bilities, even though they were still considered underpowered at the same time.
As the advantages of computer technology in the ’90s pushed businesses to adapt and change or be at a disadvantage, enterprise computing began to take hold. Data centers were being built across the industry to allow businesses to make use of computer technology for business operations. This was now the time of on-premises computing, where large data centers became the core drivers of business processes and where data and data security, as always, became a powerful weapon for large corporations. Then came the new millennium with its focus on online communication, global networking, and the Internet, which changed the landscape once again.
The cycle is now back to utility computing in the guise of cloud computing. But this time around, cloud computing looks to be a better option than just utility computing. It creates opportunities for business and allows smaller organizations to wield the same technological prowess as that of their larger counterparts. Small businesses with no capital to set up their own on-premises data centers can either rent an infrastructure where they can set up their own platforms or leverage already available ones and pay only for what they use. The barrier for entry is really low, which allows small businesses to play in the same field as the big boys.
But this is not exactly the same as when utility computing was apparently the only choice and then after a time on-premises became the only choice. Now both are legitimate choices, with their own pros and cons. One might argue that one of these is better than the other, but the truth is really more neutral: it’s situational. We will shed light on the nuances of each one so you may determine for yourself which fits your own situation.