Capacity requirements put additional constraints on the environment where the throughput and latency goals can be met. These requirements might be expressed either in terms of computing resources or in cold hard cash. The ways in which such requirements can be described can, for example, take the following form:

  • The system must be deployed on Android devices with less than 512 MB of memory
  • The system must be deployed on Amazon EC2 The maximum required instance size must not exceed the configuration c3.xlarge (8 G, 4 cores)
  • The monthly invoice from Amazon EC2 for running the system must not exceed $12,000

Thus, capacity has to be taken into account when fulfilling the latency and throughput requirements. With unlimited computing power, any kind of latency and throughput targets could be met, yet in the real world the budget and other constraints have a tendency to set limits on the resources one can use.