For the short term (until we sell one) there are three cars in my household. A manual transmission, an automatic and a CVT (continuous variable transmission). This makes me uniquely qualified to write about Cloud Computing.
That’s because Cloud Computing is yet another area in which the manual/automatic transmission analogy can be put to good use. We can even stretch it to a 4-layer analogy (now that’s elasticity):
That’s traditional IT. Scaling up or down is done manually, by a skilled operator. It’s usually not rocket science but it takes practice to do it well. At least if you want it to be reliable, smooth and mostly unnoticed by the passengers.
Manumatic transmission (a.k.a. Tiptronic)
The driver still decides when to shift up or down, but only gives the command. The actual process of shifting is automated. This is how many Cloud-hosted applications work. The scale-up/down action is automated but, still contingent on being triggered by an administrator. Which is what most IaaS-deployed apps should probably aspire to at this point in time despite the glossy brochures about everything being entirely automated.
That’s when the scale up/down process is not just automated in its execution but also triggered automatically, based on some metrics (e.g. load, response time) and some policies. The scenario described in the aforementioned glossy brochures.
Continuous variable transmission
That’s when the notion of discrete gears goes away. You don’t think in terms of what gear you’re in but how much torque you want. On the IT side, you’re in PaaS territory. You don’t measure the number of servers, but rather a continuously variable application capacity metric. At least in theory (most PaaS implementations often betray the underlying work, e.g. via a spike in application response time when the app is not-so-transparently deployed to a new node).
OK, that’s the analogy. There are many more of the same kind. Would you like to hear how hybrid Cloud deployments (private+public) are like hybrid cars (gas+electric)? How virtualization is like carpooling (including how you can also be inconvenienced by the BO of a co-hosted VM)? Do you want to know why painting flames on the side of your servers doesn’t make them go faster?
Driving and IT management have a lot in common, including bringing out the foul-mouth in us when things go wrong.
So, anyone wants to buy a manual VW Golf Turbo? Low mileage. Cloud-checked.