I recently gave a talk on the key trends in cloud computing and to set the stage, I was asked to describe the spectrum of cloud computing options from private cloud computing to public cloud hosting.
Here is a snapshot of one slide I used to describe this spectrum of cloud computing. On one end of the spectrum you have private cloud computing – dedicated to a single company, designed around high availability (in most cases), secure and very capable of delivering SOX, PCI and HIPAA compliance. On the other end of the spectrum, we have public cloud computing with computing as a utility model. The public cloud is a multi-tenant solution that is designed to deliver the lowest cost with questionable security and significant challenges in achieving compliance.
Closer to the private cloud, but still in the shared cloud computing model is managed cloud hosting. Just like the private cloud, the managed cloud is designed around high availability to eliminate all single points of failure in the IT infrastructure, in stark contrast to the public cloud which is designed to achieve commodity pricing by eliminating points of redundancy and cost.
Hybrid cloud hosting provides a mix between the private cloud, managed cloud hosting, dedicated non-virtualized servers, and in some cases public cloud computing.
The cloud computing spectrum provides a model of options and tradeoffs when selecting a cloud computing delivery platform. The further to the left, the more architectural control you have over the solution, the more secure and the easier it is to assure compliance to a breadth of standards. As you move to the right in the cloud computing spectrum, the less secure or complaint the cloud and the more the focus shifts to cost and the ability to purchase computing by the hour.
So which cloud computing model is right for you? It depends on your requirements. Key issues to consider include your security, compliance and availability requirements.