SaaS, scalable pools, buzzwords and half-truths.
Hidden behind the idea of being able to instantly spin up virtual machines in the cloud and make SaaS hosted solutions available on heterogeneous client platforms is the dirty secret that *someone* has to be paying for the bare-metal those pooled virtual resources share. I can only give your machine more memory or more procs or more *machines* on the fly because I have that capacity in reserve in the DC where my cloud resides. Clouds are vapor, but cloud environments reside on physical environments.
That is why a PRIVATE cloud loses many of the benefits of a real cloud. Now I've got all the headaches of a cloud (and there are some major liabilities), and I've still got the real hardware costs on my end. I can only spin up a new server quickly for the accounting department because I have extra capacity just sitting there in my DC. It is smoke-and-mirrors. CIOs like it because instead of asking for redundant physical machines that seem like a cost center because they're just sitting there, now he can say, "We need these racks and these SANs and these switches and all this cabling to be able to scale our capacity in real time". But you're still buying more equipment than you need and leaving it in reserve as it rapidly depreciates. And the scaling out and scaling back on the fly... sure. When you're done with a machine you can spin it down and stop paying the TCO costs associated with having it live. Licensing, maintenance, even the real electricity and cooling it takes to have that virtual machine running. But you still have that hardware sitting there. This seems to be the biggest slight-of-hand that cloud proponents are pushing... I'm still fixated on a private cloud, of course. In a public cloud, sure... I'm using 10 machines and paying a metered rate... when I drop down to 8, I'm saving money. But the hosting location is building that capacity overhead into the metered cost. *I'm* paying for it, and they're making money in the bargain, or they wouldn't be doing it. It isn't clear to me that over the lifetime that I'll save money moving to the cloud. It might just be cheaper for me to keep it in-house than pay monthly metered usage fees that have profit enough to include all the costs I would have to pay *anyhow*.
No? When I think about the pitches about what the cloud is, how it works, and why it makes sense, I frequently feel like someone is trying to pull a Jedi mind trick on me. The logic doesn't make sense. I'm just shifting my cost center somewhere else.
The pitch that it is so easy to scale ignores the fact that there have to be REAL resources beneath the virtualized cloud environment. If I've got a machine with 32GB of RAM and you've got two VMs running on it using 16GB each and you add another machine that needs 16GB... that (generally) isn't going to happen. I know there are other ways that we can roll those VMs around transparently in a way we couldn't with bare metal to get you to a place where we can do this non-disruptively... but I've still got to have those resources somewhere to scale - which means they were just sitting there doing *nothing* before your need arose. The cloud claims it can make something out of nothing - but it can't.
Great article - though. You covered a lot of ground that has a lot of people confused, here.
Contributr 
