Defining the true meaning of cloud

Defining the true meaning of cloud

Summary: A true cloud has all four of these defining components. Most definitions get it wrong because they focus on just one or two of these components instead of looking at the whole picture.


In the midst of the Enterprise Irregulars discussion that ensued from Michael Krigsman's Monday blog post Cloud-based IT failure halts Virgin flights — when many of us complained it wasn't a cloud instance at all — Michael posted this plea:

"How does one determine whether a solution is 'cloud' or not — what are the rules?"

It's a fair question. When explaining cloud, I often allude to the ancient Indian parable of the blind men and the elephant, in which each man grabbed a different part of the elephant and, because they didn't see the whole creature, took it to be something quite different. The point being that cloud is exactly like that, and most of the definitions out there get it wrong because they focus on a part rather than the whole.

My definition highlights four components, which I'll set out below in a moment (or hear me explain them in this webinar, which I recorded last week). Three of the four components are often talked about individually, and the fourth is too often neglected altogether. The neglected component is one that I call 'cloud scale', and it's the one that sets the all-important context in which all the others come together as a unified whole. Yet it's the one most often ignored or denied, especially when people try to implement what they perceive as cloud on a private computing stack. What I say to them is almost becoming something of a catchphrase: "You can't take computing out of the cloud and still call it cloud computing."

The whole point of cloud computing is to be able to operate in the cloud — in that global, 24x7, connected universe where you can instantly reach and interact with your customers, your partners and your mobile employees, as well as tapping into an expanding cornucopia of third-party resources and services that can help you achieve business results faster, better and at lower cost. Those who say that cloud is just a deployment choice, just a technology option, have shut their eyes to the wider opportunity and potential that the cloud context opens up. They're still building application platforms and business systems that are designed without any acknowledgement of that global web of connections and resources — as if in today's business environment, being connected is just an afterthought, an optional extra. Maybe for some applications it is, but their numbers are shrinking daily.

Page 2: The 4 defining features of cloud »

«  Page 1: If it's not in the cloud, it's not cloud computing

So having set the scene, let's walk through the four components that make up my definition of cloud.

Abstracted infrastructure. In most cases, that means virtualization, but I've chosen a slightly more generic term because virtualization implies a specific technology choice and the key point here is that the underlying infrastructure isn't tied to any specific hardware or operating software. In theory, any component could be swopped out or exchanged without affecting the operation of whatever is running above. Crucially, the abstraction provides elasticity to scale usage up or down without having to stop to upgrade the underlying infrastructure.

As-a-service infrastructure. The pairing of virtualization with automated provisioning and management has been a crucial element in enabling the on-demand, pay-as-you-go nature of public cloud. When enterprises talk about implementing private cloud, these are the ingredients they focus on, and there's no doubt that they deliver enormous cost savings and productivity gains when implemented privately. But these components alone are not the only constituents of cloud. Taking existing platforms and applications and implementing them on a pay-as-you-go, virtual machine is not cloud computing. You'll still have enormous extra management overhead, duplicated resources and wasted redundant capacity — and gain none of the additional benefits of a fully cloud-scale environment.

Multi-tenancy. Sharing a single, pooled, operational instance of the entire top-to-bottom infrastructure is more than simply a vendor convenience; it's the only way to really achieve cloud scale. Look beyond the individual application or service and consider also the surrounding as-a-service infrastructure and any connecting framework to other cloud resources. Understand the value of having all of that infrastructure constantly tuned and refreshed to keep pace with the demands of its diverse user base across hundreds or even thousands of tenants. The most conservative among them will constantly probe for potential risks and weaknesses. The most progressive will clamor for new functionality to be brought into production as rapidly as possible. Every tenant benefits from sharing the collective results of those two extremes and all points in-between, keeping the shared infrastructure both battle-hardened and future-proofed. Every tweak and enhancement is instantly available to every tenant as soon as it's live.

Cloud scale. It's no accident that cloud architectures are multi-tenant — just look at Google, Amazon, Facebook and all the rest. If you start from a need to perform at cloud scale, you build a multi-tenant infrastructure. It's the only way to deliver the walk-up, on-demand, elastic scalability of the cloud with the 24x7 reliability and performance that the environment demands. Cloud scale consists of all of this globally connected operational capacity, coupled with the bandwidth and open APIs required to effortlessly interact with other resources and opportunities and platforms as they become available in the global public cloud. A computing architecture can have all the other attributes of cloud, but without this cloud scale dimension, it will not be able to keep pace with the operational demands, the overwhelming connectivity and the continuous rapid evolution of the cloud environment.

Also read:

Seeking the true meaning of SaaS

Topics: Hardware, Cloud, Servers, Storage, Virtualization

Phil Wainewright

About Phil Wainewright

Since 1998, Phil Wainewright has been a thought leader in cloud computing as a blogger, analyst and consultant.

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  • Sorry but...

    "Those who say that cloud is just a deployment choice, just a technology option, have shut their eyes to the wider opportunity and potential that the cloud context opens up."

    That "potential" has yet to prove itself in any meaningful way.

    I understand your deep desire for everyone to simply accept this "potential" as having a basis in fact but it's just not there yet and may never be.

    Other "potentials" include:

    Loss of connectivity. (Always happens at the worst possible time.)

    Huge security risks, especially if its in the US and its "Patriot Act". (Do you realy trust ALL of Google's or Microsoft's employees?)

    The cloud becomes an equalizer instead of computing being a competitive tool. (Hey we are all using the same platform and applications, somehow we all seem to get the same results.)

    Loss of responsiveness to user needs. It was not a cost factor that drove PC's into the enterprise, it was the ability for the user to do things others were not doing and the ability to make changes quickly. The paradigm of centralised computing (big iron and terminals) simply didn't fit users needs. Adding fancy graphics isn't going to change that.
    • Excellent! Very well said!

      P. Douglas
    • The cloud will have its place

      @No_Ax_to_Grind <br><br>Only many of us have substantive doubts as to how big a place that shall ultimately encompass, for many of the reasons you've alluded to.
    • RE: Defining the true meaning of cloud

      @No_Ax_to_Grind <br><br>I would have to disagree with you. You doubt the "potential" but take a look at a cloud product like By being a Cloud/Subscription product, it can be leveraged by both the largest of enterprise companies while also a SMB company. Prior to Cloud, it was impossible for a SMB to get an enterprise-class product not only due to price, but support, installation, maintenance, etc. <br><br>"Loss of connectivity. (Always happens at the worst possible time.)" This does happen, however, from my experience the company's network is the likely cause not the ISP or the Cloud provider like Amazon or Salesforce. Since it is cloud, i am able to still get to the data from an alternate internet connection such as home, Starbucks or my cell.<br><br>"Huge security risks, especially if its in the US and its "Patriot Act". (Do you realy trust ALL of Google's or Microsoft's employees?)" Are you ok that 150,000+ employees of Citibank have access to your bank account? Doesn't seem to be much issue when talking about money, but it is when talking about other business needs. But seriously, it is important to perform due diligence on Cloud providers if you will be trusting them to manage your information. Bottom line is that HOW your information is managed and secured is more important than WHO is managing and securing. I have found that 90%+ times an established Cloud provider does a better job than the typical company. They HAVE TO or they wouldn't be in business.<br><br>"Loss of responsiveness to user needs." This seems to be true if the user needs are atypical. The opposite seems to be true if you are looking for functionality that others want as well.
    • Google Security Risk

      I don't know about the others you mentioned, but at this time I would trust Google more than most other IT departments or hosting providers. I can understand why enterprise clients trust their own infrastructure more, but perhaps some companies need to ask whether their own infrastructure is more or less risky than Google... also keep in mind that private cloud infrastructure allows enterprise clients to secure their own cloud leveraging their own private infrastructure... almost limiting the risk to that which is associated with only their own infrastructure and IT departments. The "cloud" is the elephant he's mentioning, isn't it?
      Asher Bond
      • True

        @Asher Bond You've got a point - using an open source platform to preform business functions always poses a security risk. Thoughts on using proprietary CMS's for cloud computing?

        -Elizabeth @Auctori
  • Example?

    Can you provide an example of a cloud service that matches you definition?
    • Re: Examples

      @SAASISV asked, 'Can you provide an example of a cloud service that matches you definition?'

      Amazon Web Services (but not single-instance apps that run on top of, say, EC2); Azure; heroku;; Successfactors; NetSuite; Workday; and many others.
      phil wainewright
  • Well said

    Hi Phil - couldn't agree more - to take the public out of cloud is to remove the two key benefits; scale yes but more fundamentally I think its about philosophy and a strategic decision to leverage the wider connected world. Fundamentally - at least to me - cloud is a business disruption not a technology one. I wrote more about this same subject a few months ago My only disagreement is that I don't think that cloud platforms are about infrastructure - the focus of your post - but rather will grow to encompass everything required to deliver business in the cloud. As a result see also Thanks. Ian
    • RE: Defining the true meaning of cloud

      @iansthomas, just read your article and felt in so much agreement I thought you were channeling me.

      @philw, just wrote a similar article (actual combination of sorts with yours and @ianthomas) for Tnooz, a travel tech sector pub. Part 1 is more definitional ( and Part 2 is the 10 Reasons Why you need to understand your s/w providers architecture (
  • RE: Defining the true meaning of cloud

    You hit the nail on the head Phil...

    "The whole point of cloud computing is to be able to operate in the cloud... as well as tapping into an expanding cornucopia of third-party resources and services that can help you achieve business results faster, better and at lower cost."

    Check out this blog post from IBM developerWorks on "Defining Cloud Computing" I'd be curious to know what you think.

    You can reach me on Twitter @jhodge88
    • RE: Defining the true meaning of cloud

      @jhodge88 I read it and it is OK but lacks most of the business orientation of Phil's plus it tries to flog private cloud which is natural enough if you're in the business of selling stuff to IT managers.
  • Cloud_Zone

    Cloud computing is evolving fast. Today, organisations understand that they can use the model to cut costs, increase efficiency and be more responsive to changing market demands.
  • Cost?

    If cloud scale is so good why does it cost $1,500 per month for 10TB on AMAZON for such a simple service?
  • Great!

    Fantastic post. Here???s a tool that lets you build your cloud database apps without coding