Peak-to-average
The ratio between peak traffic and average traffic. It tells you how bursty a workload is.
Definition
Peak-to-average (often called peak-to-average ratio) is the ratio between peak demand and average demand.
Example: average is 1k QPS and peak is 10k QPS, so peak-to-average is 10×.
Why it matters
A system that handles the average can still fall over at peak.
Peak-to-average is how you reason about headroom, autoscaling, caching, and queues.