An error budget is the amount of failure an SLO allows over its window: 100% minus the target. For a 99.9% SLO over 30 days it is 0.1% of requests, or about 43 minutes of full downtime. Teams spend it on releases and experiments and protect it when it runs low.
Why it matters
The error budget turns reliability into a shared number. While budget is healthy, teams ship faster. When it’s burning, they slow down and fix reliability first.
24 min left
- Release 2.406 min
- Dependency blip9 min
- Experiment4 min
- Still to spend24 min
Healthy budget: ship faster. Burning budget: fix reliability first.
How fast the budget is being spent is the burn rate. What a team agrees to do as it runs low is the error budget policy.
How SteadyNines protects error budgets