Now that the benefits of cloud computing are firming up and organizations are moving beyond “if” into “how”, the question of public vs. private clouds is taking center stage. There are those who view private cloud as just virtualization or not really cloud at all.
Companies like Google and now Microsoft are pushing an all-public cloud model by offering services such as Google Apps and Office 365. While other companies are hoping to eliminate the security concerns around public clouds by looking to bring similar capabilities in-house as a private cloud workplace service.
In all of this noise about cloud, there remains a lack of clarity around what the cloud really is, where it exists, and how you can incorporate it into your existing enterprise and do something meaningful. This confusion is part of the reason cloud comes off the peak of expectation and enters into the trough of disillusionment. Just because the rest of the market may go through this process, it doesn’t mean that your own enterprise will. People are beginning to realize that each organization can have its own definition of cloud.
This confusion is most obvious in the range of terminology used to describe cloud offerings. “Public cloud”, “private cloud” and “hybrid cloud” seem to be confusing at various levels and just because you understand them from your context, it doesn’t mean that when you talk with someone else it means the same thing to them.
I’ve written numerous posts about cloud over the past few years and have been talking about the concept since the turn of the century, but I don’t think I’ve ever written down my definitions:
- Public cloud – This is a multi-tenant, pay by-the-drink service that is highly scalable and dynamic and accessed over the public Internet. It may be infrastructure, its operations, software, or even access to the capabilities of personnel running a business process. It allows for access to environments (someone else’s capital investment and intellectual property) to meet your business needs. This is ideal for when usage needs are undetermined and the data transport and security issues can be overcome.
- Private cloud – An intranet based set of leveraged hardware, software and services. It is centrally managed, usually charged out within the organization for usage. It is also highly scalable and relatively dynamic. For large organizations that can afford the capability it provides a more clearly defined and auditable secure environment. It may be hosted by someone else or within an organizations internal data center – after all it’s the network that provides the data transport and hardly anyone owns that internally anymore. This is ideal for when you know generally how much computing resources you will need and the data transport and security issues require greater control.
- Hybrid cloud – This is a combination of the two environments, usually requiring specially created software and management tools and approaches to allow the work to flow between the environments. Almost every organization of size that does anything with public cloud will likely need to have a hybrid cloud environment in their enterprise architecture.
Another area of confusion is caused by there being a couple of things about the move to cloud that I think are totally underestimated.
1) The integration effort between software and environments. The data just doesn’t magically keep itself in sync.
2) The need for consistent user interface to present information in context.
3) The security and data transport concerns. You can only work on the data if you can get it to where the work needs to get done, in a secure fashion.
4) The exit strategy – what will you do when you are done with a cloud service provider? How will you get the data that started out as megabytes and ended up as petabytes into the new environment?
Some people ask “Are we headed to an all-cloud business model in the future? Are in-house IT departments headed for extinction? Is Outsourcing dead?” Probably not, yet cloud computing is here to stay and its implementation is growing. Gartner forecasts revenue for cloud services in 2010 to increase 16.6% over 2009, up to $58.6 billion.
There are numerous opportunities to apply this computing abundance in new ways for those who want to plan for it. I'd say one of the first things organizations need to do is define their priorities and set expectations that any efforts will make.