An event is anything of interest that happens in code, including expected behavior such as a completed upload and unexpected behavior such as a failed shopping-basket write. section 2.3
Events become useful operational signals when they are recorded and interpreted with context:
- Logs capture events in a textual payload; timestamps and labels support correlation, while structured output makes events more actionable. section 2.3
- Common levels distinguish fine-grained debugging from expected production behavior and unexpected or erroneous behavior. section 2.3
- Terms such as log line, log item, and log entry are generally interchangeable with log event. section 2.3
Instrumentation can capture events automatically or through code. Auto-instrumentation offers a baseline view but treats a service as a black box; manual instrumentation adds business-logic signals by configuring OpenTelemetry and creating events for traces or metrics. section 4.3.1
