August 2018
Beginner
594 pages
22h 33m
English
Content preview from Software Architect's Handbook
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
Start your free trial
Calculating availability based on time
Availability can be calculated with the following formula:
MTBF is the mean time between failures, which is the average time between two failures of the system. MTTR is the mean time to repair, which is the average time to troubleshoot and repair the system back to its operational state. Only unplanned outages are considered when calculating system downtime.
To achieve high availability, which is considered five nines, or 99.999% availability, your software system can only be down for 5 minutes and 15 seconds or less during the course of a whole year! The following table shows some sample availability ...