@Override
    public int getNumberMissedCycles() {
        if (!isActive.get()) {
            return 0;
        }
        return (int) ((int) (System.currentTimeMillis() - lastUpdated) / refreshIntervalMs);
    }
A default strategy for the dynamic server list updater to update.
(refactored and moved here from {@link com.netflix.loadbalancer.DynamicServerListLoadBalancer})

@author David Liu
ribbon-loadbalancer/src/main/java/com/netflix/loadbalancer/PollingServerListUpdater.java