Multi-window burn-rate alerting, anything above 14.4× will eat the monthly budget in a day.
At a glance
The rate at which the merchant is consuming their monthly error budget, expressed as a multiple of the sustainable rate. A burn rate of 1× means errors are happening at exactly the rate the SLO permits over the month; 14.4× means at this rate the entire month’s error budget will be consumed in a single day. For a merchant, this is “are we running through our acceptable-error allowance faster than we should?” Above 14.4× is an emergency; it predicts SLO breach within hours.
Calculation
Calculated automatically from your Datadog data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A US apparel brand on BigCommerce with two Datadog SLOs:- SLO-CHK Checkout availability: 99.9% over 30 days. Budget: 43.2 minutes of unavailability per month.
- SLO-SRCH Search latency below 800 ms p95: 99.5% over 30 days. Budget: 3.6 hours of breach per month.
The headline displays 17.2× with a P1 alert because the highest-burn-rate SLO is in fast-burn territory. Three observations the merchant should read:
- The checkout SLO is in fast-burn. A 17.2× burn rate over the next 24 hours would consume 24/720 × 17.2 = 57% of the entire monthly budget. The SLO has 67% remaining now; at 17.2× burn for 24 hours, only 10% would remain by tomorrow. Engineering must act now or risk breach within hours.
- The search SLO is in slow-bleed. 3.1× burn rate is concerning but not urgent: a deploy degraded latency slightly two days ago and 12% budget remains. Page on-call but with P3 severity. The team has time to plan a fix during normal hours rather than emergency-page someone.
- The two SLOs have very different action paths. Fast-burn (checkout) demands immediate rollback; slow-bleed (search) demands a planned investigation. Conflating them produces poor outcomes; reading them separately produces appropriate response.
- The 14.4× threshold is calibrated, not arbitrary. It comes from the Google SRE workbook: at 14.4×, an SLO over 30 days is consumed in 24 hours, which is the longest-but-still-actionable response window before breach. Below 14.4× = “you have time to plan a fix”; above = “fix now or accept the breach”.
- Burn rate makes alert thresholds portable. A 99.9% SLO and a 99.99% SLO can have the same raw error count but very different burn rates because the budgets are 10x different. Engineering teams running multiple SLOs at different targets benefit from this normalisation.
- Fast-burn vs slow-bleed need different responses. Fast-burn = “rollback now”; slow-bleed = “schedule a fix this sprint”. Mistaking one for the other produces either over-paging (treating slow-bleed as fast-burn) or under-paging (treating fast-burn as slow-bleed). Multi-window alerting is the standard practice that distinguishes them.
Sibling cards merchants should reference together
Reconciling against the vendor’s own dashboard
Where to look in Datadog:SLO List for the master list with per-SLO burn rate and budget remaining. SLO Detail (any SLO) for the time-series of compliance and burn rate. Monitors → SLO Alert Templates for the multi-window burn-rate alerts.Why our number may legitimately differ from Datadog’s UI:
Cross-connector reconciliation: