opentelemetry-dotnet-instrumentation/docs/log-trace-correlation.md

Log to trace correlation

Note Automatic log to trace correlation provided by OpenTelemetry .NET Automatic Instrumentation currently works only for .NET applications using Microsoft.Extensions.Logging. See #2310 and config for more details.

OpenTelemetry .NET SDK automatically correlates logs to trace data. When logs are emitted in the context of an active trace, trace context fields TraceId, SpanId, TraceState are automatically populated.

The following are logs produced by the sample console application:

"logRecords": [
    {
        "timeUnixNano": "1679392614538226700",
        "severityNumber": 9,
        "severityText": "Information",
        "body": {
            "stringValue": "Success! Today is: {Date:MMMM dd, yyyy}"
        },
        "flags": 1,
        "traceId": "21df288eada1ce4ace6c40f39a6d7ce1",
        "spanId": "a80119e5a05fed5a"
    }
]

Further reading:

• OpenTelemetry .NET SDK
• OpenTelemetry Specification