Observabilitet er evnen til å forstå et systems interne tilstand fra dets eksterne utdata — gjennom logger, metrikker og traces. Det er essensielt for å drifte, debugge og vedlikeholde systemer (spesielt distribuerte), der du ikke kan administrere det du ikke kan se.
De tre pilarene i observabilitet
LOGS → timestamped records of events (what happened) → detailed, for debugging specific issues
METRICS → numerical measurements over time (CPU, latency, request rate, error rate) →
aggregate health/performance; dashboards; alerting
TRACES → follow a request's path through the system (across services) → understand flows,
find bottlenecks/failures in DISTRIBUTED systems (which service was slow?)
→ together: understand WHAT happened, the OVERALL state, and the PATH of requests.
