The joke is that no matter how many redundancies, the complexity is so beyond human's ability to map at once, that you always miss a single point of failure. E

The joke is that no matter how many redundancies, the complexity is so beyond human's ability to map at once, that you always miss a single point of failure. Each failure scenario must be gracefully handled in each subpart to take into account all possible impact on the whole system. You'll always get a random crap you never heard of destroying an assumption you made in your own crap. I remember an instance where a national mobile phone provider in France got a single db outage but during a large sms day (think new year), so the failover happened but totally overloaded the new servers, and it created a chain reaction to other providers to a point you couldnt read your email for a day or two because of inability to get smses. Why is that random db in a provider I dont even use impacting my google account ? Because the system is distributed.