// time.
		r := rand.New(rand.NewSource(time.Now().UnixNano()))
		randSleepFor := func() time.Duration {
			return 5*time.Second + time.Duration(float64(5*time.Second)*r.Float64())
		}

		timer := time.NewTimer(randSleepFor())
		defer timer.Stop()

		var (
			quit     bool
			traceMsg string
			notify   bool // if status changed, notify nodes to reload rebalance metadata
		)

		for {
			select {