Private cloud computing model has recently become one of the most used buzzwords in the IT industry. Many new products and technologies are positioned to power private clouds, however its definition remains broad, which is probably a fair attribute for a new computing model. So, what is it? Lets look in the history: the adoption of the set of technologies used for public Internet sites to power information delivery to users on internal networks began more than a decade ago, thus creating the intranet - and competition for the client-server computing model. A very similar process is now happening with regard to the private cloud, i.e. private clouds to public clouds comparison is in many ways similar to the comparison of intranet to the Internet. Private clouds use the same technology as public clouds, but within an internal network.
The essential components/technology for the private cloud computing infrastructure are the same as for the public cloud computing:
- HTTP as a communication protocol- XML/JSON and other data serialization types for data exchange- language neutrality (i.e. collaborating components may be written by different programmers, using different languages, on different platforms)- loose-coupling (components do not depend on each other at compile time, and the failure of one component does not fail the entire system)- service orientation - this would be a very broad item to include in this list, but I want to emphasize one aspect of it: focus on the concentrated clusters with specific computing functionality, utilizing technologies mentioned above. For example: web reporting server, user profile service, authentication and authorization service, etc.
The size of organizations using private clouds does not matter - it may be a small company with a few employees or a multinational enterprise. Many companies do in fact already use loosely-coupled web services on their intranets, with many above-mentioned attributes, without formally acknowledging the fact that the architecture in place already has private cloud computing clusters or a close prototype of a private cloud. The next step in evolving a private cloud computing model in such companies is to recognize that the private cloud computing model is already on premises, create internal commitment to adhere to this model, and continue to evolve it by both building custom web services and deploying cloud-friendly products and technologies such as web reporting server (http://www.arnicasoftware.com/products/reporting-software/overview.aspx), web forms generators, custom web services (such as product data access), employee self-services (profile update, user directory lookup), etc.