Probability, Statistics, Distributed Systems, Software Engineering, Interview Questions.
servers and multiply that by (1-p) for each k servers that are up and multiply by p for each (N-k) servers that are down. Thus probability that at-least (N+1)/2 servers are up is (denoted by ‘f’): f = (sum k=(N+1)/2 to N)(N chooses k) * (1-p)^k * p^(N-k) >= 0.9999 For a given probability of failure