kubernetes/staging/src/k8s.io/apiserver/pkg/util/flowcontrol/dropped_requests_tracker.go

const maxRetryAfter …

type DroppedRequestsTracker …

type unixStat …

type droppedRequestsStats …

func newDroppedRequestsStats(nowUnix int64) *droppedRequestsStats { … }

func (s *droppedRequestsStats) recordDroppedRequest(unixTime int64) { … }

func (s *droppedRequestsStats) updateHistory(unixTime int64, count int64) { … }

// updateRetryAfterIfNeededLocked updates the retryAfter based on the number of
// dropped requests in the last `retryAfter` seconds:
//   - if there were less than `retryAfter` dropped requests, it decreases
//     retryAfter
//   - if there were at least 3*`retryAfter` dropped requests, it increases
//     retryAfter
//
// The rationale behind these numbers being fairly low is that APF is queuing
// requests and rejecting (dropping) them is a last resort, which is not expected
// unless a given priority level is actually overloaded.
//
// Additionally, we rate-limit the increases of retryAfter to wait at least
// `retryAfter' seconds after the previous increase to avoid multiple bumps
// on a single spike.
//
// We're working with the interval [unixTime-retryAfter, unixTime).
func (s *droppedRequestsStats) updateRetryAfterIfNeededLocked(unixTime int64) { … }

type droppedRequestsTracker …

// NewDroppedRequestsTracker is creating a new instance of
// DroppedRequestsTracker.
func NewDroppedRequestsTracker() DroppedRequestsTracker { … }

func newDroppedRequestsTracker(now func() time.Time) *droppedRequestsTracker { … }

func (t *droppedRequestsTracker) RecordDroppedRequest(plName string) { … }

func (t *droppedRequestsTracker) GetRetryAfter(plName string) int64 { … }