What is burn-rate alerting, and why is it better than alerting on raw error rates?

Summary

Burn rate is how fast you are consuming the error budget relative to the SLO: a burn rate of 1 uses exactly the budget over the window; 14.4 exhausts a 30-day budget in about 2 days. Alerting on burn rate pages only when the SLO is genuinely threatened, with urgency proportional to the speed of the burn.

Longer Answer

The SRE workbook recommends multiwindow, multi-burn-rate alerts. For example, page if 2% of a 30-day budget is consumed in 1 hour (burn rate 14.4) confirmed by a 5-minute window, and if 5% is consumed in 6 hours (burn rate 6); open a ticket for slower burns (10% in 3 days). The short window makes alerts reset quickly after recovery; the long window prevents paging on brief blips.

Compared with "error rate > 1% for 5 minutes", burn-rate alerts reduce false pages for low-impact blips and still catch slow leaks before the budget is gone.

Key Points

• Burn rate = speed of budget consumption.
• Page on fast burns, ticket on slow burns.
• Multiwindow: long to detect, short to reset.
• Fewer false pages, better coverage.

What interviewers look for

Knowing the multiwindow, multi-burn-rate approach and why it improves precision and recall.