# Connecting OpenTelemetry traces and logs


This sample shows how to configure an NServiceBus endpoint to link OpenTelemetry traces and logs together.

## Configuration

First, configure OpenTelemetry to capture NServiceBus traces:

<!-- snippet: otel-config -->

```cs
builder.Services.AddOpenTelemetry()
    .ConfigureResource(resourceBuilder => resourceBuilder.AddService(endpointName))
    .WithTracing(traceBuilder =>
    {
        traceBuilder.AddSource("NServiceBus.*");
        traceBuilder.AddConsoleExporter();
    });
```

<!-- endsnippet -->

In this example, all telemetry is sent to a `ConsoleExporter`, but any OpenTelemetry-compliant exporter will work.

Next, connect the logs emitted by the application to the traces as follows:

<!-- snippet: otel-logging -->

```cs
builder.Logging.AddOpenTelemetry(loggingOptions =>
{
    loggingOptions.IncludeFormattedMessage = true;
    loggingOptions.IncludeScopes = true;
    loggingOptions.ParseStateValues = true;
    loggingOptions.AddConsoleExporter();
});
```

<!-- endsnippet -->

This will apply the OpenTelemetry logging format to all the logs. More importantly, it will [correlate all logs](https://opentelemetry.io/docs/specs/otel/logs/#log-correlation) to the active traces.
This means that each log statement will include a `TraceId` and `SpanId` as part of the log entry.



## Running the sample

When running the sample, the following log statement from the message handler:

<!-- snippet: log-statement -->

```cs
logger.LogInformation("Received message #{Number}", message.Number);
```

<!-- endsnippet -->

will lead to the following output:

```text
info: MyMessageHandler[0]
Received message #54
LogRecord.Timestamp:               2022-06-28T09:02:34.5342602Z
LogRecord.TraceId:                 964b320925ab08cd2134c02d0abe920d
LogRecord.SpanId:                  066fce94c5438add
LogRecord.TraceFlags:              Recorded
LogRecord.CategoryName:            MyMessageHandler
LogRecord.Severity:                Info
LogRecord.SeverityText:            Information
LogRecord.FormattedMessage:        Received message #54
LogRecord.Body:                    Received message #{Number}
LogRecord.Attributes (Key:Value):
    Number: 54
    OriginalFormat (a.k.a Body): Received message #{Number}
LogRecord.ScopeValues (Key:Value):
[Scope.0]:SpanId: 066fce94c5438add
[Scope.0]:TraceId: 964b320925ab08cd2134c02d0abe920d
[Scope.0]:ParentId: e595cc6a4d9b0768
```

The console will also show information for the captured traces:

```text
Activity.TraceId:            964b320925ab08cd2134c02d0abe920d
Activity.SpanId:             066fce94c5438add
Activity.TraceFlags:         Recorded
Activity.ParentSpanId:       e595cc6a4d9b0768
Activity.DisplayName:        MyMessageHandler
Activity.Kind:               Internal
Activity.StartTime:          2022-06-28T09:02:34.5322602Z
Activity.Duration:           00:00:00.0017675
Activity.Tags:
    nservicebus.handler.handler_type: MyMessageHandler
StatusCode: Ok
Instrumentation scope (ActivitySource):
    Name: NServiceBus.Core
    Version: 0.1.0
Resource associated with Activity:
    service.name: Samples.OpenTelemetry.MyEndpoint
    service.instance.id: 93d66e53-7537-4e21-99f9-e62b579b5fa3
    telemetry.sdk.name: opentelemetry
    telemetry.sdk.language: dotnet
    telemetry.sdk.version: 1.15.3
```