Availability in numbers
This is worth to note. Availability in numbers Availability is often quantified by uptime (or downtime) as a percentage of time the service is available. Availability is generally measured in number of 9s–a service with 99.99% availability is described as having four 9s. 99.9% availability - three 9s Duration Acceptable downtime Downtime per year 8h 45min 57s Downtime per month 43m 49.7s Downtime per week 10m 4.8s Downtime per day 1m 26.4s 99.99% availability - four 9s Duration Acceptable downtime Downtime per year 52min 35.7s Downtime per month 4m 23s Downtime per week 1m 5s Downtime per day 8.6s For more you can check https://github.com/donnemartin/system-design-primer ...