The Gradual Shift

April 2, 2008

More about cloud computing

Here’s a short quote from Billy Marshall (rPath): A Big Switch or a Gradual Shift?

The historical metaphor that Carr effectively uses to demonstrate the likelihood of this pending change is the switch from locally produced electrical power to regionally produced electrical power delivered via a high performing electrical grid infrastructure. In Carr’s metaphor electricity is analogous to applications and the electrical grid is analogous to the Internet. There are clearly some parallels, but I believe the metaphor is flawed because information applications are more analogous to hair dryers, drill presses, and die stamping machines (i.e. applications that consume electricity) as opposed to the electricity itself.

Billy goes on to point out how companies are always going to need specific things from these electricity-consuming objects, hypervisors are more like the power transformers that convert and reliably step down electricity (into standardized, repeatable delivery units), and virtual appliances are more like the hair dryers, drill presses, and die stamping machines:

When applications can reliably plug into a grid to receive power in a standardized and repeatable manner, it will be increasingly popular to let someone else deliver the power of the grid while the individual companies focus on the *design of the application* (i.e. the drill press, the chip digester, the ore smelter).

I think it’s a good way to frame things, an expansion I’d offer is that it is not just hypervisors that are this transformation/delivery mechanism, but also all of the other cluster infrastructure needed to make a leasable datacenter. The security, scheduling, efficiency, and enforcement mechanisms/policies that must be in effect. The hypervisor is in all likelihood going to be the most popular core technology, but there’s a lot more to making a safe, solvent, and usefully leasable cluster.

At the edge of the cluster and beyond, there’s also all the technology and lessons of grid computing to draw from. A field where virtualization is a mechanism being incorporated in a larger pre-established context (cf. papers from our group and many others). In the analogy, facets of grid computing perhaps get us into “buying clubs”, “electricity markets”, “consumer protection”, etc. (and how about rolling blackouts).