The Uptime Meter(SM) measures the actual availability of installed Stratus systems worldwide. This meter is re-calculated daily, based on actual reported service incidents.
Uptime Calculation
- Uptime of the Stratus ftServer family is computed and updated daily based on all reported service incidents for all ftServer systems worldwide, over the preceding 6-month period
- Both hardware-related and software-related incidents are included in this availability measurement
- Outages are only counted if there is an impact to production
Definition of Uptime
"Uptime" or "Availability" is defined here as the fraction of a time period that a system is fully operational; for example, if a system is fully operational 100 hours per week, its availability is 100/168 = 60%
Availability is normally expressed in 9's; for example, "five nines" means that a system is fully operational 99.999% of the time, corresponding to an average of less than 6 minutes downtime per year. The chart below shows what statistical impact various availability levels have on average downtime..
Availability
Level |
Average Yearly Downtime |
|
87 hours, 40 minutes |
| High Availability |
99.9%
99.95%
99.99% |
|
8 hours, 46 minutes
4 hours, 23 minutes
52 minutes, 36 seconds |
| Continuous Availability |
99.999%
99.9999% |
|
5 minutes, 16 seconds
31.6 seconds |
|