DEVOPS / A CONCEPT NOTE
SLI / SLO / SLA
measuring 'is it working?'
Overview · mechanism
pitfall · examples
01 / THE SHORT VERSION
The idea in a few sentences.
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.
02 / FOLLOW THE MECHANISM
How measurement to agreement flows
SLI metric
system logs response times (e.g., this request took 150ms).
SLO target
monitors compliance over time (e.g., target 99.9% requests are < 200ms).
Error Budget
calculates permitted failures. Violating SLO freezes new releases to focus on stability.
SLA penalty
if SLO breach impacts business legal SLA limits, client receives refunds.
04 / COMMAND NOTES
Read the command, then the result.
Inspect the flags and arguments before trying an example. Snippets can need local setup, replacement values, or resources in your own environment.
test alert metrics calculations syntax
promtool check metrics05 / CHECK YOURSELF
Could you explain SLI / SLO / SLA to a teammate?
Try it out loud in two sentences: what it is, and the one detail that changes the picture. If you stall, the gap is the part to reread.
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