Load testing
A key element of preparation in these cases is load testing.
Load testing is creating a simulated load that goes to an increased level of traffic. It can be done in an explorative way, i.e., let's find out what the limits of our system are; or in a confirmative way, i.e., let's double-check that we can reach this level of traffic.
Load testing is typically done not in production environments, but in staging ones, replicating the configuration and hardware in production, though it is normal to create a final load test verifying that the configuration in the production environment is the correct one.
An interesting part of load testing analysis in cloud environments is to ensure that any autoscaling in the system works correctly, so it provisions more hardware automatically when receiving greater load, and deletes it when it's not necessary. Caution is required here, as a full load test to the maximum capacity of the cluster can be expensive...
