Connect .NET trace data with logs using OpenTelemetry instrumentation 🔗
The Splunk Distribution of OpenTelemetry .NET automatically exports logs enriched with tracing context from any application that uses logging API from Microsoft.Extensions.Logging for logging.
Application logs are enriched with tracing metadata and then exported to a local instance of the OpenTelemetry Collector in OTLP
format.
The following is an example of logs produced by a sample console application:
2024-02-15 15:23:17 2024-02-15T13:23:17.704Z info ResourceLog #0
2024-02-15 15:23:17 Resource SchemaURL:
2024-02-15 15:23:17 Resource attributes:
2024-02-15 15:23:17 -> splunk.distro.version: Str(1.4.0)
2024-02-15 15:23:17 -> container.id: Str(c894cdb646a29616b5f713195cf810be898ca99c311cac8d9d25d8561dd6964b)
2024-02-15 15:23:17 -> telemetry.distro.name: Str(splunk-otel-dotnet)
2024-02-15 15:23:17 -> telemetry.distro.version: Str(1.4.0)
2024-02-15 15:23:17 -> telemetry.sdk.name: Str(opentelemetry)
2024-02-15 15:23:17 -> telemetry.sdk.language: Str(dotnet)
2024-02-15 15:23:17 -> telemetry.sdk.version: Str(1.7.0)
2024-02-15 15:23:17 -> service.name: Str(Example.LogTraceCorrelation.Console)
2024-02-15 15:23:17 -> deployment.environment: Str(dev)
2024-02-15 15:23:17 -> service.version: Str(1.0.0)
2024-02-15 15:23:17 ScopeLogs #0
2024-02-15 15:23:17 ScopeLogs SchemaURL:
2024-02-15 15:23:17 InstrumentationScope
2024-02-15 15:23:17 LogRecord #0
2024-02-15 15:23:17 ObservedTimestamp: 2024-02-15 13:23:13.1358363 +0000 UTC
2024-02-15 15:23:17 Timestamp: 2024-02-15 13:23:13.1358363 +0000 UTC
2024-02-15 15:23:17 SeverityText: Information
2024-02-15 15:23:17 SeverityNumber: Info(9)
2024-02-15 15:23:17 Body: Str(Hello from {activity})
2024-02-15 15:23:17 Attributes:
2024-02-15 15:23:17 -> activity: Str(LogWrappingActivity)
2024-02-15 15:23:17 Trace ID: 17512c0247942df04fb30e6090eacb2c
2024-02-15 15:23:17 Span ID: dc281b062178e72f
2024-02-15 15:23:17 Flags: 1
Check compatibility and requirements 🔗
Note
Automatic log to trace correlation only works for .NET applications. For .NET Framework use manual correlation. See Manual log to trace correlation.
Microsoft.Extensions.Logging
version 8.0.0
and higher are supported.
Activate log correlation 🔗
The instrumentation turns on automatic log to trace correlation by default.
If you need to turn off logs enrichment and export, set the value of OTEL_DOTNET_AUTO_LOGS_ENABLED
environment variable to false
.
Trace metadata in log statements 🔗
Individual log records, if exported inside the scope of an active activity, contain the following trace context information:
Trace identifier
Span identifier
Trace flags
Logs produced by an application always have the following set of OpenTelemetry resource attributes :
telemetry.sdk.name
with constant value ofopentelemetry
telemetry.sdk.language
with constant value ofdotnet
telemetry.sdk.version
with current version ofOpenTelemetry .NET SDK
telemetry.distro.name
with constant value ofsplunk-otel-dotnet
telemetry.distro.version
with current version ofSplunk Distribution of OpenTelemetry .NET
splunk.distro.version
with current version ofSplunk Distribution of OpenTelemetry .NET
(deprecated attribute)
Additionally, the instrumentation adds the following attributes:
service.name
, as defined by theOTEL_SERVICE_NAME
environment variableAny attribute configured using the
OTEL_RESOURCE_ATTRIBUTES
environment variableAny attribute added by configured resource detectors, like
container.id
Manual log to trace correlation 🔗
You can configure logging libraries to include tracing attributes in logs written to existing logs destination.
NLog
🔗
You can use NLog.DiagnosticSource . See the NLog official documentation for more information.
Serilog
🔗
You can use one of the available enrichers, like Serilog.Enrichers.Span or create your own enricher to add trace context as properties to log events.