Cloud computing has sparked a degree of interest that we haven’t seen since the introduction of client / server technology. We believe it’s an early stage / early adopter market where most of the new providers still have much serious work to do in perfecting their market offerings. But that’s what we help them do and we love it.
Nevertheless clouds are murky places and there’s some dense fog out there. There’s much hype and vapour too. In our customer-facing project, we were offered managed hosting, leased product based managed data centre solutions, bespoke clouds (how can they be?), co-location and every other form of externally managed solution that ever was, real or imagined. We were offered imaginary cloud too – the ideas of a zealous salesman on what his company might provide as and when they decided to do so. But it was sold to us as if their cloud offering was available now and it was no small or obscure company either.
We’ll go on to talk about our market and customer findings but first, for the sake of our non-technical readers, we’ll talk about what cloud is in ordinary language.
So what is Cloud?
Gartner’s definition works well for us:
“A style of computing where scalable and elastic IT-enabled capabilities are delivered as a service to customers using Internet technologies.” We also describe five defining attributes of cloud computing: service-based, scalable and elastic, shared, metered by use, uses Internet technologies. A key to cloud computing is an opaque boundary between the customer and the provider. Graphically, that looks like this:
When the customer does not see the implementation behind the boundary, and the provider doesn’t care who the customer is, you have a public cloud service. So what is private cloud?
Private cloud is “A form of cloud computing where service access is limited or the customer has some control/ownership of the service implementation.” This may also be taken to imply the exclusive use of dedicated external physical resources.
We like the President of CSC’s definition that I’m going to paraphrase from memory. “Cloud computing is the delivery of computing facilities whenever you want, wherever you want, however much you need for as long as you need without cost penalty.”
That works well for us. Gartner’s diagram is helpful too.
But there are lots of businesses trying to jump on the cloud bandwagon that, in fact, are not offering cloud. Consider this assertion:
“Cloud computing is about providing computing as a utility…over the Internet.
The difference with Cloud is in the way computing is delivered:
- we provide you with infrastructure as a service IaaS
- supply is on demand
- delivery is via the internet
- costs are rental, based on usage.”
It’s true that one of the differences is the way it is delivered but it’s not the only one. Scalability and elasticity together are one of the five defining attributes of cloud. They are not present here since what’s being sold is simply managed hosting.
So is virtualisation a defining attribute of the cloud? Many hosting suppliers say so. They claim, “managed hosting + virtualisation = cloud computing.” That’s simply what it is. It’s managed hosting with virtualisation and not cloud computing.
As this is my introductory piece I’ll say what virtualisation is for the majority of suppliers. Virtualisation here means “server virtualisation” which is about partitioning one physical server into several virtual servers or machines. Each virtual machine can interact independently with other devices, applications, data and users as though it were a separate physical resource.
Hypervisor software is the magic ingredient that makes virtualisation possible. This software sits between the hardware and the operating system and decouples the operating system and applications from the hardware. The hypervisor assigns the amount of access that the operating systems and applications have to the processor and other hardware resources, such as memory and disk input/output.
Virtualisation can mean much more than this but that will do fine for now. There’s nothing new about it. Virtualisation was first introduced in the 1960s by IBM to boost utilisation of large, expensive mainframe computers by partitioning them into logical, separate virtual machines that could run multiple applications and processes at the same time.
Virtualisation, which is one of Gartner’s “top technologies for 2010”, is not necessarily synonymous with cloud, although it may offer significant cost benefits in the deployment of cloud technologies. Cloud technologies that offer elasticity and scalability also present cost benefits in themselves. To put it more simply, you pay only for what you need and use. You don’t pay for under-utilised in-house server networks.
And what do all those initials mean – IaaS, PaaS and SaaS?
Kate Craig-Wood, managing director of Memset very kindly provided me with this helpful diagram that she produced as part of her work on the Government (G-) cloud programme:
Kate writes, “The diagram shows what we agreed we mean by Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (right hand side) and the areas encompassed by the individual terms infrastructure / platform / software on the left. A better term than “software” might be “application” since the platform part is also really just software, but SaaS has already gained wide acceptance.
It is assumed that “as a service” means all services within the definition are fully integrated up to and including the respective level, thus incorporating any sub-levels. Therefore, SaaS providers could either sub-contract to a PaaS provider, or would incorporate the PaaS themselves and provide it as part of the SaaS “stack”. In turn the IaaS could be sub-contracted or incorporated. The customer would see an integrated service.”
This works well as a schematic but practically speaking, Platform as a Service is frequently addressed by the Infrastructure as a Service provider and the virtualisation layer may or may not be present, although it usually is. Interestingly I have yet to see a cloud provider describe their offering as PaaS.
In our next posts, we’ll look at some of the commercial and market issues around the cloud and what’s going on in the front line.
Geoffrey Wilkins
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