Cloud Defined

  • Article

“Nature is a mutable cloud which is always and never the same.” – Ralph Waldo Emerson

It’s tough to talk about clouds until we have a simple, working definition.  While ramping for Azure Security guidance, we defined the cloud as follows:

A cloud is a managed infrastructure providing network, compute, and storage capabilities.   It has the following 3 key characteristics:

  1. Managed / abstracted infrastructure
  2. Elastic resources
  3. Pay-for-play / utility computing

This simple frame helps us identify what is cloud, and what is not.

That’s not the only definition in town though.  Here are a few others that I found useful ...

Berkeley Cloud Definition
In Above the Clouds: A Berkeley View of Cloud Computing, U.C. Berkeley Reliable Adaptive Distributed Systems Laboratory define the cloud as follows:

“Cloud Computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the datacenters that provide those services. ... From a hardware point of view, three aspects are new in Cloud Computing.

  1. The illusion of infinite computing resources available on demand ...
    users to plan far ahead for provisioning.
  2. The elimination of an up-front commitment by Cloud users ...
    increase hardware resources only when there is an increase in their needs.
  3. The ability to pay for use of computing resources on a short-term basis as needed ...”

In A Break in the Clouds: Towards a Cloud Definition
In A Break in the Clouds: Towards a Cloud Definition, Vaquero et al define cloud as follows:

“Clouds are a large pool of easily usable and accessible virtualized resources (such as hardware, development platforms and/or services). These resources can be dynamically re-configured to adjust to a variable load (scale), allowing also for an optimum resource utilization. This pool of resources is typically exploited by a pay-
per-use model in which guarantees are offered by the Infrastructure Provider by means of customized SLAs.”

What’s your working definition of “cloud” that you’ve found helpful?