Welcome to the third blog in the series on Cloud computing. This blog looks at four types of Cloud deployment in common usage. A cloud deployment type is a specific cloud environment, as explained below.
The four deployment types are:
- private Cloud
- public Cloud
- hybrid Cloud
- community Cloud
The four types of Cloud deployment listed above will be described a brief comparison of how the various Clouds are deployed and some of the advantages and disadvantages of each will then follow..
As the name would suggest a private Cloud is owned by an organisation. The organisation then deploy the Cloud for their own exclusive use. Due to the investment by the organisation the infrastructure of the Cloud will be tailored to the specific needs of the organisation. This usually results in a bespoke Cloud designed for a specific purpose.
Banking and telecommunication infrastructures are based on the private Cloud methodology.
Although an individual organisation owns and has exclusive use of the Cloud it is not uncommon for a private Cloud to be designed or managed by outsourced 3rd party resources.
Due to the architecture and insularity of private Clouds the users are contractually bound to good behaviour.
This aids the security of, and the organisation’s faith in their Cloud.
It would be both incorrect and grossly unfair to merely state that a public Cloud is the opposite of a private Cloud. The infrastructure of a public Cloud is owned by the Cloud provider and leased to its customers.
The infrastructure can be managed by the Cloud provider, outsourced to a 3rd party or a mixture of the two.
Due to the basic fact that the Cloud is used by multiple users, often referred to as multi-tennanted servers, public Clouds are seen as being less secure than private Clouds with some justification. This point will be discussed in further detail in a future blog regarding cloud security. At this point it is sufficient to say that users, whether they are organisations or individuals, are reliant upon the infrastructure properties provided by the Cloud provider to establish trust.
Amazon, RackSpace, Salesforce and Google docs are all examples of public clouds.
A hybrid cloud is a mix of either a private or community Cloud and a public Cloud. A popular use of hybrid Cloud is where an organisation with a private Cloud outsources its backup storage to a public Cloud thus creating a hybrid cloud solution to its IT needs.
A community Cloud is created when a group of organisations from one domain generate a specific cloud solution to meet the specific needs of the domain.
The domain in this instance could be an industry sector such as Banking or Insurance, a holding company with various subsidiary companies for example, Associated Newspapers.
Comparison of Cloud Deployment Types
Users of private and community Clouds have strong relationships with Cloud providers. There is a ‘relationship’ of mutual benefit or a desire to meet shared goals. This relationship creates a high degree of trust in the Cloud. Although the architecture has some importance it is not as significant as the architecture within a public Cloud.
Hybrid Cloud deployment requires careful consideration as high resilience, reliability and a possible reduction in IT costs are very attractive but the drawbacks may not be acceptable to the risk appetite of the organisation. The risk appetite is the amount of risk the organisation is prepared to expose itself too, whether that is financial or reputational.
A hybrid Cloud consisting of a private or community Cloud hosting critical applications with a public Cloud being used to host the web front-end and to store protected backup would appear to be a logical solution. However…
A badly configured hybrid Cloud, or more frequently a badly managed hybrid Cloud solution poses a high risk to any organisation considering a hybrid Cloud. A highly secure private Cloud with a less secure public Cloud. Potential cyber attackers would attack the weakest link, in this case the public Cloud, and then gain access to the private Cloud.
When a hybrid Cloud solution is being considered the risk analysis must be careful and thorough throughout the whole project. Careful management of the Cloud is needed not only when outsourcing services but also when data is being moved between Cloud infrastructures.
It is clear from the brief overview above that the area of Cloud computing is a very broad-brush approach to four very different solutions, each bringing their own challenges and rewards. As with most areas of technology cost and suitability need to be factored in to the decision making process.
In the next blog article in this series the concept of securing the Cloud will be considered.