five-nines uptime

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What is five-nines uptime?

Five-nines uptime – or 99.999% – refers to the amount of time a network or service is available to users or other systems over a certain period, usually a year. This means there will be about 5.26 minutes of total downtime, either planned or unplanned.

Six-nines (99.9999%) = .526 minutes
Five-nines  (99.999%) = 5.26 minutes
Four-nines (99.99%) = 53 minutes
Three-nines (99.9%) = 8 Hours and 46 Minutes
Two-nines (99%) = 3 Days, 15 Hours, 36 Minutes

Five-nines uptime is achieved by adding redundancy, failover, fast restart/respawn of processes so that no single component or combination of component failures can crash the entire system. Steps are also taken to ensure the crossover between redundant systems doesn’t become a failure point. The availability is also enhanced when failures are detectable as they occur and reliance on staff is reduced in order to cut human error.

Five nines of uptime is becoming more critical for organizations that rely on high operational performance, such as hospitals or data centers. Practically speaking, five-nines and above uptime is considered “always on”.