News for hackers. Stuff that matters.
Re:Apple iCloud Experiencing Issues by 3JPLW on Thursday July 04, 2019 @01:59PM (#20356492)
No the cluster size isn't fixed, nor is the event rate — the clusters are chosen purely based upon what an "unusually long" time between events would be. That's precisely how the rate ends up canceling itself out. Given this formulation, the expected cluster size is always e, regardless of how you define celebrity. That's what makes it fun.

Now the human psychology part that this doesn't cover is that typically when you have two or three A-listers die, well, then you start seeing all the B- C- and D-listers that also died in the same period that you would have otherwise ignored.

Re:Apple iCloud Experiencing Issues by emerongi on Thursday July 04, 2019 @02:13PM (#20356610)
Can you calculate the chance of the cluster size being >5 when we can cluster events within a one-week period and the rate of events is one every 2 months (debatable, but feels right to me)?

I think that would just end this discussion. I don't know how to calculate that, but my intuition says the resulting chance is low.

Re:Apple iCloud Experiencing Issues by appleiigs on Thursday July 04, 2019 @04:02PM (#20357299)
I don't know how to do the math, but my python simulation says zero.

  import random

  service_providers = 20
  servers_threshold = 5
  up_time_threshold = 0.999**7 # prob down in week
  years = 20
  occurrences = 0

  # run sim 10,000 times
  for i in range(0, 10000):
      servers_down = False
    
      # simulate weeks in 20 years
      for j in range(1, 52*years):
          how_many_down_this_week = 0
        
          # run up times for service providers
          for s in range(0, service_providers):
              up_time = random.random()
              if up_time > up_time_threshold:
                  how_many_down_this_week += 1

          # did they go down?
          if how_many_down_this_week > servers_threshold:
              servers_down = True

      if servers_down == True:
          occurrences += 1

  print(occurrences)
Re:Apple iCloud Experiencing Issues by joshuamorton on Thursday July 04, 2019 @04:09PM (#20357361)
Given those parameters, you'd expect to see something every 100,000 years or so. (poisson distribution, lambda=1/8, k=5, the result is like 7e-7).