SLO

SRE / DevOps concept Service Level Objective.

Definition

A SLO (Service Level Objective) is an objective applied to a SLI: 'the SLI must exceed X% over the measurement window'. It's the internal SRE team commitment. Distinct from SLA (customer contract) which typically includes penalties. Google recommendation: SLO always stricter than SLA to absorb noise.

Origin

Google SRE Book 2016 concept, popularised via the error budget practice.

Example in context

EDI SLO: 99.5% of INVOICs processed in under 30 seconds on a 30-day rolling window.

Related terms

• SLI — underlying metric.
• Error budget — budget derived from SLO.