When you are planning hardware resources for a web presence that needs to be available, you tend to assume the worst case scenario, the maximum connections that need to be supported – and then some to make sure you don’t go down when there is one or 1000 more connections. Cloud hosting changes the view and strategy of capacity planning. In fact, we are now talking about reverse capacity planning. Forrester Analyst James Staten highlights a stealth startup that is subscribing to an IaaS cloud and “most of the time pays next to nothing to do this”.
In fact, this company, which requested to remain anonymous, is planning for a minimum monthly bill and scales from there. There is no pre-allocation of resources, as the cloud scales with the demand. If there is no demand, there is a minimum bill. If there are thousands of users, the capacity is available on demand. Staten says that the model should be replicated and it may even be improved: “You can do the same but don’t stop once you’ve determined your base capacity. Can you make it even smaller? The answer is most likely yes. Because if there is a peak, then there is also a trough.“
In the case of the stealth startup, the code was tweaked to minimize the footprint, which enabled them to reduce the footprint even further. What “they really needed persistently was their services’ home page and that could be cached in a content delivery network. So when their service has no traffic at all, they have no instances running on their IaaS platform. Once the cache has been hit they then fire up the minimal footprint (which they tuned down to a single virtual machine) and then scale up from here.”
Staten says that if “you can find the trough then you can game the system to your advantage.” Maybe “gaming” goes a bit far. It is what cloud computing is meant to be.