Comparison
Burst capacityvsCapacity planning
Burst capacity
the instance was fast for twenty minutes and then abruptly slow, because it had been spending credits it had run out of.
Capacity available above a baseline for limited periods, either as a cloud instance's credit mechanism or as an autoscaler's fast-path. It is genuinely economical for spiky, low-average workloads and actively dangerous for anything sustained, because performance falls off a cliff rather than degrading. The signature symptom is a service that is fine in testing and slow after an hour in production.
Full entry →Capacity planning
you work out from load tests how much traffic one instance handles, and how many you need for Black Friday.
Determining the resources required to meet demand at a target latency, with headroom for failure and spikes. It requires a measured per-instance capacity, not an assumed one. Plan for the loss of a zone or a region as well as the peak, or your headroom disappears exactly when you need it.
Full entry →