Function ensureStableKey

pkg/usagestats/reporter.go:137–170

ensureStableKey ensures that the cluster seed is stable for at least 30seconds. This is required when using gossiping kv client like memberlist which will never have the same seed but will converge eventually.

(ctx context.Context, kvClient kv.Client, logger log.Logger)

// This is required when using gossiping kv client like memberlist which will never have the same seed
// but will converge eventually.
func ensureStableKey(ctx context.Context, kvClient kv.Client, logger log.Logger) *ClusterSeed {
	var (
		previous    *ClusterSeed
		stableCount int
	)
	for {
		select {
		case <-time.After(stabilityCheckInterval):
		case <-ctx.Done():
			return nil
		}

		value, err := kvClient.Get(ctx, seedKey)
		if err != nil {
			level.Debug(logger).Log("msg", "failed to get cluster seed key for stability check", "err", err)
			continue
		}
		if seed, ok := value.(*ClusterSeed); ok && seed != nil {
			if previous == nil {
				previous = seed
				continue
			}
			if previous.UID != seed.UID {
				previous = seed
				stableCount = 0
				continue
			}
			stableCount++
			if stableCount > stabilityMinimumRequired {
				return seed
			}
		}
	}
}

func (rep *Reporter) init(ctx context.Context) {
	ctx, span := tracer.Start(ctx, "UsageReporter.init")