Defining scalability objectives

Achieving scalability requires your application architecture to be scalable in order to leverage the highly scalable infrastructure services provided by AWS cloud. Your application should respond proportionally to the increase in resources consumed, and be operationally efficient and cost effective. For example, if you lift-and-shift your on-premise application to the cloud and vertically scale your instances to meet increasing load, then it is likely that it will either become very expensive, your application's increasing resource requirements will necessitate another move to larger instances soon, or both. Hence, it is vital that you design your application to work together with the infrastructure to meet your scalability requirements. In order to design, implement, and operate effectively, you should define an initial set of scalability metrics, for example, the number of requests to be served per second, average and peak number of simultaneous users...