Check whether current SLI performance is meeting your defined SLO target.
SLO compliance measures how your actual success rate compares to a committed target: actual_slo = (total − failed) ÷ total × 100. Burn rate expresses this as a multiple of your allowed error budget consumption rate — a burn rate of 1x means you're consuming your error budget exactly on pace to exhaust it by the end of the period; a burn rate of 10x means you'd exhaust a 30-day budget in 3 days.
Actual SLO
actualSLO = ((totalRequests - failedRequests) / totalRequests) × 100
Burn rate
burnRate = actualErrorRate / allowedErrorRate
It means your current error rate exceeds what's sustainable to stay within the SLO for the full measurement period — if it continues at this rate, you'll breach your error budget before the period ends.
Actual SLO percentage is a point-in-time snapshot of overall compliance; burn rate expresses velocity — how fast you're using up the allowed error budget relative to a sustainable pace.
Most mature SRE practices alert on burn rate (e.g. multi-window multi-burn-rate alerts) because it catches fast-developing problems early, well before the cumulative SLO percentage itself would breach.
This depends on your SLI definition — commonly 5xx errors, requests exceeding a latency threshold, or business-logic failures. Be consistent about the definition across your SLO reporting.