docList.clear();
                    accessResultList.clear();

                    updateTime = systemHelper.getCurrentTimeAsLong() - updateTime;

                    final long interval = updateInterval - updateTime;
                    if (interval > 0) {
                        // sleep
                        ThreadUtil.sleep(interval); // 10 sec (default)

	// This goroutine owns the cache.
	var saverWg sync.WaitGroup
	saverWg.Add(1)
	go func() {
		// Add jitter to the update time so multiple sets don't sync up.
		updateTime := 30*time.Second + time.Duration(float64(10*time.Second)*rand.Float64())
		t := time.NewTicker(updateTime)
		defer t.Stop()
		defer saverWg.Done()
		var lastSave time.Time

		for {
			select {
			case <-t.C: