19. Assume one of the cluster nodes fails every 50 hours, and the other clusters never fail. The repairing task takes average 2 hours. i) What is the availability of the cluster? What is the yearly failure cost if each onehour downtime costs 1000? ii) What is the yearly failure cost if each one-hour downtime costs 1000? iii) Suggest an approach for which the yearly failure cost can be reduce. Give an example assuming the MTTF is still 50 hours.