So... a blog about Cloud Computing.

First off, let's take a definition from Wikipedia (as of today anyway - these things change pretty quickly):

"Cloud Computing is a computing paradigm shift in which computing is moved away from personal computers or an individual application server to a "cloud" of computers. Users of the cloud only need to be concerned with the computing service being asked for, because the underlying details of how it is achieved are hidden."

Now, as an architect it's a pretty standard technique to look at technological entities from a number of different views. For example, one (implementation) view of the Cloud is the that of massive mirrored data centers and huge undersea fiberoptic cables, brilliantly described by George Gilder's Wired magazine article The Information Factories. Another view is to look at the Cloud* from a functional or use case perspective: exactly what functionality do the services within the Cloud provide? (Online storage, payments, salesforce automation... - basically all the WSDL out there).

However, more recently I've been thinking about a logical view of the Cloud: how do we start putting a logical conceptual structure and language around an innately nebulous concept like "the Cloud of services"?

Now, the word "Service" is a many-overloaded term , and in most conversations about "services" related to the Cloud people are talking about "web services" and "service oriented architecture" (SOA) - however, I prefer to abstract back out again to the wider economic definition of a service (again, quoting Wikipedia):

"A service provision is an economic activity that does not result in ownership ...that creates benefits by facilitating either a change in customers, a change in their physical possessions, or a change in their intangible assets."

Or, more succinctly: an economic service delivers an outcome, (which is hopefully measurable) to facilitate change. And, an economic service usually has a price of one sort or another.

My logical view would define the Cloud thus:

"The Cloud" = "the universe of all economic services"

(More than a nod to 20th century set theory here). ;-)

Here is a picture of "the Cloud of Economic Services", with a few examples pencilled in, including their economic pricing models in parentheses for discussion another time.

Now, consider the following statement, where X is any good or service:

"buy X" = "buy a licence to execute the business process "procure X"

If you agree with this formulation, then it follows that every economic good or service can be decoupled from its pricing model, and can instead be expressed purely as a licensable business process, with a single entry point exposed as a web service. That is: every economic service can be expressed as a web service:

The Cloud of all economic services = The Cloud of all web services.

Obviously the reasoning above is purely abstract, and there will be real-world challenges to expressing every economic service in WSDL (latency is the big one which springs to mind), but nonetheless I think that this forms the underpinnings of a model of how to rapidly make SOA commercially viable on a global scale - in particular, how to make a common marketplace of all (web) services in the Cloud work. More on this subject soon...

[*As an aside, being a survivor from Dotcom 1.0 circa 1995 I was disappointed when the various linguistic authorities around the world institutionalized "internet" with a lower case "i" - imho there is only one Internet (yes, there may be many little internets all operating in splendid isolation from each other, but there is only one Internet that we all connect to...), so like the Earth, the Sun and the Moon it's a proper noun! Anyway, in the same vein, rolling the argument forward to 2008: conceptually there can be only one Cloud, so I shall be capitalizing forthwith! ;-) ]