TOPIC DEVOPS
SLI / SLO / SLA measuring 'is it working?'
IN 10 SECONDS
SLI (Indicator) is the actual metric (e.g. latency). SLO (Objective) is the target goal (e.g. 99% under 200ms). SLA (Agreement) is the legal promise to customers with penalties.
GOTCHA Setting SLOs to 100% is impossible and expensive. It leaves no room for failures, blocking all product updates and code deployments.
HOW MEASUREMENT TO AGREEMENT FLOWS
01 SLI metric system logs response times (e.g., this request took 150ms).
02 SLO target monitors compliance over time (e.g., target 99.9% requests are < 200ms).
03 Error Budget calculates permitted failures. Violating SLO freezes new releases to focus on stability.
04 SLA penalty if SLO breach impacts business legal SLA limits, client receives refunds.
POKE IT YOURSELF
promtool check metrics — test alert metrics calculations syntax
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