Cloud computing isn’t so much about fundamentally new technology, but rather a change in the way that it is delivered. What is interesting is that it is driven not only by the advancement of technology, as characterized by Moore’s law (cost performance doubling every 18 months), but also by economics. The market for consumer electronics has driven down the cost of processors, memory, and disk storage such that computing is becoming relatively cheap.Even more interesting is the fact that services like Amazon’s AWS and others are setting a market price for computing. Today an hour computing costs around 10 cents per hour, and the cost to store a gigabyte for a month is around 15 cents. With the new infrastructure-as-a-service delivery model, one can also pay only for what you use and avoid the traditional capital investment corporations have made in IT.Most importantly, from a historical perspective we have for the first time an easily measured, market-determined cost of computing.
So what is it about the cloud computing that makes it so much more desirable as a model for how data centers are run? Here we have a simplified model of an enterprise IT organization supporting multiple departments. This same approach works for managed service providers if you imagine the departments are actually different customers or tenants.Watch what happens when the data center grows as more applications are added. As each new application is added, a new system configuration is created consisting of a server, operating system, storage, and the app itself. As more applications are added, the system grows in complexity. There is very little scaling advantage. Because each application setup took getting approval, and months of development, even those apps that are only used occasionally never leave for fear the department wouldn’t ever get the servers back again. This leads to the so-called “server hugging” and the resulting poor utilization and inflexible infrastructure.(While we are showing this for an enterprise, the same holds true for a managed services provider by viewing each application as a different tenant.)
In the cloud computing model things are different. In this case, the services organization provides a cloud infrastructure service, on top of which applications are deployed fully configured with their own operating system and configuration. We have de-coupled the complexity of applications from the underlying infrastructure. The application layer and the infrastructure layer are managed independently.
Cloud Computing Lew Tucker, Ph.D. VP/CTO Cloud Computing Cisco Systems, Inc QCR Research Challenges – Nov 2011 - Qatar