Tools
Uptime & SLA
"Three nines" sounds precise until you ask how much downtime it actually allows. Enter an uptime target to see the real budget you have to break, per day, week, month, and year.
- Per day
- 0
- Per week
- 0
- Per month
- 0
- Per year
- 0
Why each nine costs an order of magnitude
Every extra nine cuts your allowed downtime by roughly ten times, and the engineering to get there gets harder by about as much. Three nines gives you most of a workday of downtime a year; five nines gives you about five minutes, which no human can react to, so it has to be automated away with redundancy and failover. Picking an SLA is really picking how much money and complexity you will spend to delete minutes. For where latency fits into this, see why your app feels slow.