There's a lot of talk – some might say hot air – about cloud computing, what it is and what it is not. Ask 10 people and you will probably get 15 answers. Take the formal definition of cloud put forward by the National Institute of Standards and Technology (NIST), the section of the US Department of Commerce that for more than a …
'THE' bigger problem with definition
Literally the problem is the word 'the'.
Saying things like "my data is in the cloud" is causing confusion among the end user, by which I mean office workers storing their files and using cloud hosted applications.
The confusion that it causes is, I've found, quite a number of them believe there is just one computing cloud that spans the whole world and everything cloud related is in it. They think Office 365, Dropbox, their Google Play music and our own internal servers are all part of this "The Cloud".
It creates unreasonable expectations of how they want things to work, and also feeds fears some have about Google stealing their work when they save it.
I know I'm asking the impossible but I'd like to see corporate marketing and advertising, particularly that aimed at the end user with limited knowledge, stop referring to their services as being "in the Cloud" and start referring to them as "Microsoft's Cloud services" (replace with relevant vendor name).
Cloud != cluster
When it comes to virtualisation clusters, I always feel the word cluster is slightly mis-used. My definition of cluster (rightly or wrongly) always leads me to assume that the computing resources of each hardware node are pooled and actively shared amongst all VMs, to the point that if a hardware node goes down the software should continue to run albeit with reduced resource access if required. Though I guess that's more of an HPC/beowulf cluster definition.
In a virtualisation context, "cluster" tends to mean a collection of beefy hardware nodes with different VMs running on each. So if a hardware node goes down, it takes those VMs with it. Since your storage is usually separated these days it's simple to spin up those VMs on other hardware nodes so not a huge nightmare. Not like trying to cobble together some similar bits to get another physical machine up and running that's for sure.
But I guess to me "cloud" means you can have multiple copies of the same application/VM running on geographically separated hardware hardware nodes, with a load balancer directing requests between the available VMs. So a cluster of VMs rather than a cluster of hardware nodes. Could "cloud" be the platform that provides abstracted storage, abstracted compute nodes, and load balancing that allows your application to keep running?
Who knows, who cares, what I do know is that you're nothing without the word somewhere in your marketing bumpf.
Re: Cloud != cluster
That's because people are abbreviating, and taking off the important adjective before the word cluster.
For instance Hyper-V clusters for the most part are Failover Clusters. The keyword being failover. Doesn't imply that there are shared processing resources, but does correctly imply that there is redundancy/failover.
That being said though NUMA spanning on Hyper-V clusters does mean resource sharing to an extent.
If you ask 10 people what it is and get 15 definitions you can ascertain nobody really knows, so it's probably marketing bollocks and then carry on with your day.
I think this dictionary definition sums cloud up quite nicely:
"anything that obscures or darkens something, or causes gloom, trouble, suspicion, disgrace, etc."
Re: Dictionary defintion
Why Cloud Computing is like Teenage Sex
* It is on everybody's mind all the time.
* Everyone is talking about it all the time.
* Everyone thinks everyone else is doing it.
* Almost no one is really doing it.
* The few who are doing it are:
doing it poorly;
sure it will be better next time;
not practicing it safely.
virt & cloud is a bit like or at east similar to WWW and the internet.
Where both are technology driven one is more content based (I can access my content anywhere) and the other is virtual what? virtual hardware based.
"Virtualization, by which we mean abstracting server compute and memory capacity as well networking I/O and storage capacity, either residing in those servers or in external arrays, is obviously the key means to enable resource pooling."
Incorrect. All of the NIST definition can be achieved using physical compute resource. If they had sufficiently automated it, Rackspace would have been a true cloud years ago, and they were close. You can easily use System Center 2012 to create a private cloud with no virtualisation today. The reality is that not many people have a need to do so, but I'd imagine that the Facebook internal cloud is not virtualised on every node since their software can take full advantage of the native hardware and the ~5% overhead of the hypervisor would be bad financially at that scale.
So far as I see it...
Virtualised == Someone else hosts all the VMs
Cloud == You rewrite your software to be small transactions only with no location awareness or data organisation, and someone else stores and runs it all.
Re: So far as I see it...
@AC you're thinking of Platform as a Service rather than cloud.
Re: So far as I see it...
Perhaps, but there's only two real paradigms.
One is a rewrite to take in massively scalable but insecure databases that you don't own, and the other is you keep it as it was.
All the rest is just who hosts it, where.
Re: So far as I see it...
That would certainly be true if applications were the only thing people host, but not everyone is a software developer, and not all clouds are a platform solution, neither are they all outsourced.