What Is Five 9s in Availability Metrics?
What comes to mind when you hear that an IT component has “five 9s availability”? Five 9s availability of >= 99.999% is the peak metric for IT availability. Five 9s predicts that a measured component — whether it is a server, communication line, app, service, or any other item — will be available at least 99.999% of the time during a specific period.