[Discuss] cloud computing defined

[tmetro-blu at vl.com (Tom Metro)]

Daniel C. wrote:
> Could someone...explain to me what exactly the buzzword "cloud
> computing" means, exactly?

Oddly all of the responses to this question seem to assume you know what
"cloud" means in this context.

Technology Review has a good article on the origin of the term cloud
computing:

Who Coined 'Cloud Computing'?
http://www.technologyreview.com/business/38987/

Unfortunately a subscription is required, but I'll include a few key
bits here:

  At the time, telecom networks were already referred to as the cloud;
  in engineering drawings, a cloud represented the network.

So if "cloud" is just a visual metaphor for the Internet, then "cloud
computing," in the strictest sense, just means any computing resource
that is accessed over the public Internet.

The full definition is not universally agreed to:

  After the country's former IT czar, Vivek Kundra, pushed agencies to
  move to cheaper cloud services, procurement officials faced the
  question of what, exactly, counted as cloud computing. The government
  asked the National Institutes of Standards and Technology to come up
  with a definition. Its final draft[1], released this month, begins by
  cautioning that "cloud computing can and does mean different things to
  different people."

1.
http://csrc.nist.gov/publications/drafts/800-144/Draft-SP-800-144_cloud-computing.pdf

Another TR article summarizes and analyzes the above NIST definition:
http://www.technologyreview.com/business/38738/

  The draft document defines cloud computing as "a model for enabling
  ubiquitous, convenient, on-demand network access to a shared pool of
  configurable computing resources (e.g., networks, servers, storage,
  applications, and services) that can be rapidly provisioned and
  released with minimal management effort or service provider
  interaction."

  The definition specifies five "essential" characteristics of cloud
  computing: self-service; accessibility from desktops, laptops, and
  mobile phones; resources that are pooled among multiple users and
  applications; elastic resources that can be rapidly reapportioned as
  needed; and measured service.

The article also defined the related buzzwords: IaaS, PaaS, and SaaS.

If you're curious about the history, the "Who Coined 'Cloud Computing'?"
article goes on to dig up documented evidence for the term dating back
to 1996. The first use by Sean O'Sullivan, CEO of (now defunct) startup
NetCentric, followed a few weeks later by a mention in an internal
Compaq document by George Favaloro. (O'Sullivan and Favaloro had contact
and Compaq invested in NetCentric. So there is dispute over who used the
term first.)


> My BS detector flashes every time someone says it...

Your detector is well justified, given it is a marketing term (quoting
again from "Who Coined 'Cloud Computing'?"):

  Cloud computing still doesn't appear in the Oxford English Dictionary.
  But its use is spreading rapidly because it captures a historic shift
  in the IT industry... Other technology vendors, such as IBM and
  Oracle, have been accused of "cloud washing," or misusing the phrase
  to describe older product lines.

  Like "Web 2.0," cloud computing has become a ubiquitous piece of
  jargon that many tech executives find annoying, but also hard to
  avoid. "I hated it, but I finally gave in," says Carl Bass, president
  and CEO of Autodesk, whose company unveiled a cloud-computing
  marketing campaign in September. "I didn't think the term helped
  explain anything to people who didn't already know what it is."

  [O'Sullivan and Favaloro] Both agree that "cloud computing" was born
  as a marketing term. ... What they were hunting for was a slogan to
  link the fast-developing Internet opportunity to businesses Compaq
  knew about. "Computing was bedrock for Compaq, but now this messy
  cloud was happening," says Favaloro. "And we needed a handle to bring
  those things together."


Now try out your detector on the term "Service Oriented Architecture."
Have fun finding a clear definition for it. :-)

TR has a bunch of other articles on the topic:
http://www.technologyreview.com/business/?id=20

Including:

The Cloud Imperative (by former local Simson L. Garfinkel)
http://www.technologyreview.com/business/38710/

  Treating computing as a utility, like electricity, is an old idea. But
  now it makes financial sense--a historic shift that is reshaping the
  IT industry.
  ...
  The facts are really simple: although every organization on the
  Internet essentially is using some cloud-based service, they should
  use more. The economies of scale are becoming mind-blowing. Someone
  who wants to go buy a rack of servers probably hasn't done the math.


They also have an article on Facebook's "open hardware" servers, which
I'll discuss in a separate post.


> Is it just a way of saying that you have a distributed, parallel app
> whose individual nodes can come online (or go offline) dynamically
> without interrupting the service?

I would say that although many cloud services include those attributes,
none of them are strictly required to fit my definition, but it looks
like you are pretty close to the NIST definition. (Distributed could be
argued is required if you count the fact that user's location and the
server's location are different as being distributed. I wouldn't.)

 -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/