It sounds like you are saying that you can "cloud burst". If anyone tells you that you can "autoscale", they're full of shit. It's true that you can "spin up" more instances on AWS, but that still takes time, even with the best automation.
The advantage you get from AWS is not related to the "cloud" (eg. virtual machines hosted elsewhere). The advantage is from the virtualization. If you have unpredictable load (like many people do) then you would actually benefit far more from having physical hardware utilizing virtualization.
If you think "scalability" is simply "spin up more AWS instances", you're wrong. In the time it takes for you to "cloud burst" from 2 instances to 50 instances (which, mind you, in most cases happens in an extremely short period of time... think measured in seconds), you're site will be screwed. Even if you have the best automation setup ever known, it still takes on the order of several minutes to get an instance of a machine up and running on AWS.
"So, the next time a vendor is like, 'It's going to be so cool, you can cloud burst your way to safety.' just tell him you are not a magical unicorn." - Adam Jacob (on Cloud Bursting and Other Magical Unicorns http://youtu.be/NTijokrOw6o )
Where I currently work (a stealth mode startup), we currently have a data aggregation engine running on between 20 and 120 instances. We take advantage of the ability to spin up instances quickly, not in response to a spike in traffic (since we don't have any yet), but in response to the size of the queue of jobs (which varies depending on what we've collected). We only need 120 running for an hour or so, then we terminate them. The cost savings we get is from not having to run 120 physical boxes all the time, and there is no downside if the queue grows a little while new instances spin up.
The advantage you get from AWS is not related to the "cloud" (eg. virtual machines hosted elsewhere). The advantage is from the virtualization. If you have unpredictable load (like many people do) then you would actually benefit far more from having physical hardware utilizing virtualization.
If you think "scalability" is simply "spin up more AWS instances", you're wrong. In the time it takes for you to "cloud burst" from 2 instances to 50 instances (which, mind you, in most cases happens in an extremely short period of time... think measured in seconds), you're site will be screwed. Even if you have the best automation setup ever known, it still takes on the order of several minutes to get an instance of a machine up and running on AWS.
"So, the next time a vendor is like, 'It's going to be so cool, you can cloud burst your way to safety.' just tell him you are not a magical unicorn." - Adam Jacob (on Cloud Bursting and Other Magical Unicorns http://youtu.be/NTijokrOw6o )