SLO & Reliability
Practical
By Samson Tanimawo, PhD
Published Feb 21, 2026
4 min read
SLI vs SLO vs SLA: Practical Distinction
Three terms; specific meanings.
SLI
The measurement. Latency, error rate, availability.
What you measure.
SLO
The internal target. 99.9% uptime.
What you commit to internally.
SLA
The contractual commitment. With penalties.
What customers can sue over.