3 ms·
For reference, here is how many days/hours the system is unavailable with different percentages: 90% 36.5 days ("one nine") 95% 18.25 days 98%
by agazso 15y ago
For reference, here is how many days/hours the system is unavailable with different percentages:
90% 36.5 days ("one nine")
95% 18.25 days
98% 7.30 days
99% 3.65 days ("two nines")
99.5% 1.83 days
99.8% 17.52 hours
99.9% 8.76 hours ("three nines")
99.95% 4.38 hours
99.99% 52.56 minutes ("four nines")
99.999% 5.26 minutes ("five nines")
99.9999% 31.5 seconds ("six nines")
http://en.wikipedia.org/wiki/High_availability#Percentage_calculation http://en.wikipedia.org/wiki/High_availability#Percentage_ca...
- Terretta 15y agoIt's even easier if you measure per week instead of per year since a week has ~10,000 minutes. Then the rule of thumb is 10 minutes is 0.1%, 1 minute is 0.01%, and 6 seconds is 0.001%; or 10 mins = 99.9%, 1 min = 99.99%, and 6 seconds = 99.999% respectively. (Note that 6 seconds a week * 52 weeks = 5.2 minutes, same as the reference table above.) Programmers don't think in years, but they can think in "any given week". This rule of thumb puts things in an easy-to-remember perspective.