SLI (Service Level Indicator)

An SLI is a quantitative measure of a service level, such as latency, availability, or error rate.

What is an SLI?

A Service Level Indicator (SLI) is a carefully defined quantitative measure of some aspect of the service level, used to measure whether SLOs are being met.

Common SLIs

Availability, Latency (p50, p99), Error rate, Throughput, Durability.

Common Misconceptions

"More SLIs are better" - Focus on what matters
"SLIs must be perfect" - Good enough is acceptable
"All metrics are SLIs" - SLIs measure user experience