Concepts

SLOs and burn rate

SteadyNines calculates burn rate for every SLO continuously from your SLIs: the observed error rate divided by the error rate the SLO allows. A burn rate of 1 spends the budget exactly over the window.

Burn rateburn rate = observed error rate ÷ (1 − SLO target)

Windows and thresholds

Burn rate is checked over a long and a short window together, so a fast outage and a slow leak are both caught without paging on noise. When a burn crosses your threshold, a situation opens.

Budget spent	Long window	Short window	Burn rate
2%	1 hour	5 minutes	14.4
5%	6 hours	30 minutes	6
10%	3 days	6 hours	1