Observability

The ability to infer a system's internal state from its external telemetry (metrics, logs, traces), allowing operators to diagnose 'unknown unknowns' in dynamic, distributed environments.

Observability is a system property: it dictates how well you can understand a complex application's internal state by examining its outputs. We achieve this by collecting and correlating the three pillars of telemetry data: **Metrics** (time-series data like request latency and CPU utilization), **Logs** (discrete, timestamped events), and **Traces** (the end-to-end path of a request across services). This holistic view is critical for modern microservice and cloud-native architectures, enabling engineering teams to move beyond simple monitoring (known failures) to rapidly pinpointing the root cause of novel, unanticipated issues (unknown unknowns) in production.

https://opentelemetry.io/docs/concepts/observability-primer/