A while ago I posted my take on "Defining the Cloud" that was mostly tongue in cheek, but I also made a comment about the NIST definition of cloud:
"pay-per-use model" is considered some sort of seminal part of all
this…
In the comments, "Jeff" asked: "Can you elaborate as to why you hate the "pay per use," portion of the definition?" And I replied:
Yes, mostly because my position is that cloud should focus on
technical architecture and ppu is a pricing model. If the "cloud"
thrives (which I am not convinced it will) then demand will go up,
scalability will take over, and all the providers will convert to a
subscription service (people like ppu when they are dabbling and
subscription when they become heavy users).
So I see it as limiting* and unnecessary.
*This might seem strange since I am railing on the all-encompassing
nature of the cloud, but at this stage the buzz is too strong and the
cloud has lost all meaning.
I recently was researching the Eucalyptus open-source, private cloud offering and found this:
Myth #4: "Clouds only provide 'pay-as-you-go' access."
One of the most attractive features of the public clouds is that
they allow users to change their resource usage dynamically in response
to customer demand or offered load, and to pay only for the resources
being used from moment to moment. While this type of charging is an
important feature, it is by no means the only method a cloud can and
should support. In particular, if an allocation is to be shared among
several users within a single organization, it may make more sense to
offer a maximum resource quota on a subscription basis to keep
conflicting resource needs from causing confusion. If multiple users
are to share the VMs within a single allocation, enabling all of them
to acquire and release resources dynamically (possible resources in use
by other users of the allocation) can lead to chaos.
This is an excellent illustration of my point – putting something so arbitrary in a definition welcomes the opportunity to ignore the definition entirely (heck, there are 20+ to choose from).