One of the key elements of Cloud Computing is the deployment model.A cloud deployment model represents a specific type of cloud environment, primarily distinguished by ownership, size, and access.Generally speaking deployment is the process of making software available and ready for use. In a Cloud context deployment is basically where the software is made available, in other words where it is running.Most organizations implement the cloud infrastructure to minimize capital expenditure & regulate operating costs.
NIST’ѕ (National Institute of Standards and Technologies) оffiсiаl definition fоr cloud computing оutlinеѕ fоur сlоud deployment models. There are four basic cloud deployment models, which are:
- Public Cloud Model
- Private Cloud Model
- Hybrid Cloud Model
- Community Cloud Model
1. Public Cloud Model :
The most common and well-known deployment model is Public Cloud.The NIST definition is: the cloud infrastructure is provisioned for open use by the general public. It may be owned, managed, and operated by a business, academic, or government organization, or some combination of them. It exists on the premises of the cloud provider. Some of the examples of those companies which provide public cloud facilities are: IBM, Google, Amazon, Microsoft etc. This cloud service is open for use. This type of cloud computing is a true specimen of cloud hosting where the service providers render services to various clients.
Thе public cloud dерlоуmеnt model hаvе thе uniquе аdvаntаgе оf bеing ѕignifiсаntlу mоrе secure than ассеѕѕing infоrmаtiоn via the Intеrnеt аnd tеnd to соѕt lеѕѕ thаn рrivаtе clouds because ѕеrviсеѕ аrе more соmmоditizеd.
Advantages Of Public Cloud :
- Low Cost
- Location Independent
- High Scalability
Disadvantages Of Public Cloud :
- Low Security
- Less Customizable
2. Private Cloud Model :
Also known as an ‘internal cloud’,the other commonly used deployment model is Private Clouds. The NIST definition is: the cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g.,business units). It may be owned, managed, and operated by the organization, a third party,or some combination of them, and it may exist on or off premises.
Private clouds are a choice for companies that already own datacenter and developed IT infrastructure and have particular needs around security or performance.Private clouds permit only authorized users, providing the organizations a greater control over data and its security.
Advantages Of Private Cloud :
- Highly private and secured
- More Control
Disadvantages Of Private Cloud :
- More Cost
- Less Scalability
- Inflexible Pricing
3. Hybrid Cloud Model :
The Hybrid Cloud is a combination of both Private and Public.The NIST definition for Hybrid Cloud is: the cloud infrastructure is a composition of two or more distinct cloud infrastructures (private, community, or public) that remain unique entities, but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load balancing between clouds).Hybrid cloud, while the most complicated configuration to manage, is also the most economical model for modern companies.
Hybrid clouds can be managed in-house or by an external provider. They are highly scalable and flexible, giving users the freedom to add or remove capacity or services as demand fluctuates.
Advantages Of Hybrid Cloud :
- Cost Effective
- Secure and Flexible
Disadvantages OF Hybrid Cloud :
- Complex networking problem
- Organization’s security Compliance
4. Community Cloud Model :
The Community Cloud, while used by several constituencies, is something slightly different from a Public Cloud, The NIST definition is – The cloud infrastructure is provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be owned, managed, and operated by one or more of the organizations in the community, a third party, or some combination of them, and it may exist on or off premises.
For joint business organizations, ventures, research organizations and tenders community cloud is the appropriate solution. Costs are shared across the group, so those involved get some of the benefits of a private cloud at a lower price. In this model, responsibility for governance of the cloud can prove challenging.
Other Deployment Models
Additional variations of the four base cloud deployment models can exist. Examples include:
- Virtual Private Cloud – Also known as a “dedicated cloud” or “hosted cloud,” this model results in a self-contained cloud environment hosted and managed by a public cloud provider, and made available to a cloud consumer.
- Inter-Cloud – This model is based on an architecture comprised of two or more inter-connected clouds.