@christian@fediverseobserver I am pretty sure this is mostly due to the statistic bots pinging servers when they are temporarily down. If you ping all 20k servers there are bound to be 10 or 20 that are in the procsess of upgrading or something is up at any one time, and then they report that as dead. I have tried to look up these dead servers a number of times and seen that they were actually alive by the time I checked...