The HPA grows and shrinks a Deployment by load
A HorizontalPodAutoscaler is a feedback controller, not a capacity planner. Its default synchronization interval is fifteen seconds. Depending on its configuration, it reads resource, custom or external metrics and updates a workload’s scale subresource. The basic calculation is desiredReplicas = ceil(currentReplicas * currentMetricValue / desiredMetricValue), followed by handling for missing data, readiness, tolerances, stabilization and bounds. ...