Method CheckReady

ring/lifecycler.go:255–281

CheckReady is used to rate limit the number of ingesters that can be coming or going at any one time, by only returning true if all ingesters are active. The state latches: once we have gone ready we don't go un-ready

(ctx context.Context)

// going at any one time, by only returning true if all ingesters are active.
// The state latches: once we have gone ready we don't go un-ready
func (i *Lifecycler) CheckReady(ctx context.Context) error {
	i.readyLock.Lock()
	defer i.readyLock.Unlock()

	if i.ready {
		return nil
	}

	if err := i.checkRingHealthForReadiness(ctx); err != nil {
		// Reset the min ready duration counter.
		i.readySince = time.Time{}

		return err
	}

	// Honor the min ready duration. The duration counter start after all readiness checks have
	// passed.
	if i.readySince.IsZero() {
		i.readySince = time.Now()
	}
	if time.Since(i.readySince) < i.cfg.MinReadyDuration {
		return fmt.Errorf("waiting for %v after being ready", i.cfg.MinReadyDuration)
	}

	i.ready = true
	return nil
}

func (i *Lifecycler) checkRingHealthForReadiness(ctx context.Context) error {
	// Ensure the instance holds some tokens.