Wednesday, May 20, 2009
Public, Hosted, and Internal Clouds Defined
Like any new business technology, the early development of cloud services can be a little confusing -- as some descriptions are still open to interpretation. However, the dialog is helpful, because it enables us to focus on the true business value of data center resources.
According to Forrester Research, cloud computing platforms are more than shared multi-tenant infrastructures on the public Internet. There are three infrastructure-as-a-service (IaaS) cloud deployment options available; each has unique characteristics and economics.
Forrester’s three cloud service scenarios follow:
Which cloud service scenario is a best-fit for your business needs? Well, that depends upon a number of related factors -- such as your organizational bias for direct control, sensitivity to risk, and overall usage requirements for a cloud computing platform.
Public Cloud Scenario
Public clouds are easily accessible, multi-tenant virtualized infrastructures that are managed via a self-service portal. They deliver superior economies of scale to customers, as the infrastructure costs are spread among all users, giving each individual client an attractive low-cost, pay-per-use model.
They are managed and supported by the cloud provider and are typically homogeneous, meaning all customers share the same pool of infrastructure with limited configuration, security protections, and availability variances.
Internal Cloud Scenario
Internal clouds have similar characteristics of a public cloud, but hosted within your own data center. They leverage more of your standard processes and protections, but tend to be limited in size and scale. Your IT organization must incur the full capital and operational costs for the physical resources.
They are best for applications where you want complete control and configurability of the infrastructure and security. This most often applies to applications that manage sensitive information that is subject to strict compliance standards.
Hosted Cloud Scenario
Hosted clouds are hybrids -- a multi-tenant cloud atop rented resources, but dedicated to a single client. They help you avoid the capital and operational expense of an internal cloud, growing and shrinking the size of the cloud as needed by simply renting more resources (often added via a pay-per-use model) but providing more custom SLAs.
They give you more flexibility, where you can adjust the security as needed, specify the infrastructure elements to be used, the SLA to be applied, and set other constraints not available on a shared public cloud.
Plus, the cloud is managed by a Service Provider -- rather than your IT team. However, the economics of hosted clouds are more like managed hosting than public clouds -- since the servers that make up the cloud are typically fully dedicated to you.
Evolutionary Pathway to Cloud Services
Forrester concludes that cloud services are infrastructure deployment options that help businesses better match the needs of the application with computing resources. It’s the integration between these infrastructures that delivers the greatest value.
The goal is to speed IT service delivery, while reducing costs. Therefore, consider all options. Ask your service provider to explain their offerings, and if they can provide a pathway to virtual private cloud services -- between your data center and their cloud infrastructure.