Five-nines is something like 7 minutes of downtime throughout the entire year. At best, you might have automated failover systems that require tiny outages. No human involvement, though, unless you’re deal with some major breakage that would have killed the five-nines commitment that year, anyway.
Yes, you have automated failover systems. But, if something happens which causes those systems to fail over, you need to immediately investigate what happened and why. Even at four nines you have automatic failover, redundant system, hot spares, etc. But, you accept that sometimes not everything will work as planned and you’ll need to fix something. Five nines is just that and more.
It’s takes a human something like 5-10 minutes just to get out of bed and figure out the situation, anyway.
Right, which is why I said that four nines is your realistic maximum if you’re going to have people on call who aren’t actually at their desks. To get better than four nines you need to have around the clock coverage with people at their desks so when a system breaks you have eyes on it in something like 30s.
It’s not impossible. Large reliable websites do it all the time. It’s call 100% uptime.
No, no website does it. There is no such thing as 100% uptime. If it happens, great, but I can guarantee you that no website even aims for 5 nines of uptime.
Google is the benchmark for website availability and in 2022 they had an outage that lasted an hour, meaning they didn’t meet 4 nines for the year.
Sure, it’s measured per year, and sometimes they have some outage that breaks the record. But, it is possible to have 100% uptime throughout the year.
If you miss your SLO target for the year, then you missed your SLO target. If you’re down for 60 minutes but fine for the other 11 months, 29 days and 23 hours, you still missed your yearly SLO.
No, that’s infinite nines, which isn’t possible.
Yes, you have automated failover systems. But, if something happens which causes those systems to fail over, you need to immediately investigate what happened and why. Even at four nines you have automatic failover, redundant system, hot spares, etc. But, you accept that sometimes not everything will work as planned and you’ll need to fix something. Five nines is just that and more.
Right, which is why I said that four nines is your realistic maximum if you’re going to have people on call who aren’t actually at their desks. To get better than four nines you need to have around the clock coverage with people at their desks so when a system breaks you have eyes on it in something like 30s.
It’s not impossible. Large reliable websites do it all the time. It’s call 100% uptime.
Sure, it’s measured per year, and sometimes they have some outage that breaks the record. But, it is possible to have 100% uptime throughout the year.
No, no website does it. There is no such thing as 100% uptime. If it happens, great, but I can guarantee you that no website even aims for 5 nines of uptime.
Google is the benchmark for website availability and in 2022 they had an outage that lasted an hour, meaning they didn’t meet 4 nines for the year.
If you miss your SLO target for the year, then you missed your SLO target. If you’re down for 60 minutes but fine for the other 11 months, 29 days and 23 hours, you still missed your yearly SLO.