OpenTelemetry trace continuation

[dssldavidmorgan]

I'm experimenting with Brighter, OpenTelemetry and Sentry. So far I've got messages being written with a Sentry baggage header and an OpenTelemetry traceparent value in the message headers. Currently I'm trying something like this:

using OpenTelemetry.Context.Propagation;
using Paramore.Brighter;
using SentryTest.Messages;
using System.Diagnostics;

namespace SentryTest.Receiver;

public class TestMessageHandler : RequestHandlerAsync<TestMessage>
{
    private static readonly ActivitySource ActivitySource = new(typeof(TestMessageHandler).Assembly.GetName().Name!);
    private readonly ILogger<TestMessageHandler> _logger;

    public TestMessageHandler(ILogger<TestMessageHandler> logger)
    {
        _logger = logger;
    }

    public override async Task<TestMessage> HandleAsync(TestMessage command, CancellationToken cancellationToken = default)
    {
        var propagationContext = Propagators.DefaultTextMapPropagator.Extract(
            default,
            Context?.OriginatingMessage,
            static (carrier, key) =>
            {
                if (carrier is null)
                {
                    return [];
                }

                return key switch
                {
                    "traceparent" when !string.IsNullOrWhiteSpace(carrier.Header.TraceParent?.Value) => [carrier.Header.TraceParent.Value],
                    "baggage" when !string.IsNullOrWhiteSpace(carrier.Header.Baggage.ToString()) => [carrier.Header.Baggage.ToString()],
                    _ => []
                };
            });

        using var activity = ActivitySource.StartActivity(
            $"{nameof(TestMessageHandler)}.{nameof(HandleAsync)}",
            ActivityKind.Consumer,
            propagationContext.ActivityContext);

        Context?.Span = activity;

        _logger.LogError("Errorororoororor");

        return await base.HandleAsync(command, cancellationToken).ConfigureAwait(ContinueOnCapturedContext);
    }
}

What I'm finding is that in my handler there is no value in Context.OriginatingMessage.Header.TraceParent, even though it's present in the received message log:

{
    "header": {
        "bag": {
            "handledCount": 0,
            "messageType": "MT_EVENT",
            "topic": "apiservice.*",
            "baggage": "sentry-trace_id = 28ca60c6c56a9a295f573484c2a3a455, sentry-public_key = 4fd4b088d61f503711af2705e6cb58de, sentry-sampled = true, sentry-sample_rate = 1, sentry-sample_rand = 0.0507, sentry-release = SentryTest.Web@1.0.0+9e6541b7ce4a29786363e59cb1d542b4ba1e777e, sentry-environment = development, sentry-transaction = Event%20onclick%20->%20SentryTest.Web.Components.Pages.Home.SendMessageAsync, sentry-org_id = 4510911624839168",
            "cloudEvents_id": "019edb21-cf09-7f2b-9a7e-e4e82e918743",
            "cloudEvents_source": "http://goparamore.io/",
            "cloudEvents_specversion": "1.0",
            "cloudEvents_time": "2026-06-18T14:28:06.665Z",
            "cloudEvents_type": "testMessage",
            "traceparent": "00-28ca60c6c56a9a295f573484c2a3a455-8a9d23ce0c585080-01",
            "x-dotnet-pub-seq-no": 1,
            "deliveryTag": 1,
            "redelivered": false
        },
        "baggage": [
            {
                "Key": "sentry-trace_id",
                "Value": "28ca60c6c56a9a295f573484c2a3a455"
            },
            {
                "Key": "sentry-public_key",
                "Value": "4fd4b088d61f503711af2705e6cb58de"
            },
            {
                "Key": "sentry-sampled",
                "Value": "true"
            },
            {
                "Key": "sentry-sample_rate",
                "Value": "1"
            },
            {
                "Key": "sentry-sample_rand",
                "Value": "0.0507"
            },
            {
                "Key": "sentry-release",
                "Value": "SentryTest.Web@1.0.0+9e6541b7ce4a29786363e59cb1d542b4ba1e777e"
            },
            {
                "Key": "sentry-environment",
                "Value": "development"
            },
            {
                "Key": "sentry-transaction",
                "Value": "Event%20onclick%20->%20SentryTest.Web.Components.Pages.Home.SendMessageAsync"
            },
            {
                "Key": "sentry-org_id",
                "Value": "4510911624839168"
            }
        ],
        "contentType": {
            "boundary": null,
            "charSet": null,
            "mediaType": "application/cloudevents+json",
            "name": null,
            "parameters": [
            ]
        },
        "correlationId": "",
        "dataSchema": null,
        "dataRef": null,
        "delayed": "00:00:00",
        "handledCount": 0,
        "jobId": null,
        "messageId": "019edb21-cf09-7f2b-9a7e-e4e82e918743",
        "messageType": "MT_EVENT",
        "partitionKey": "",
        "replyTo": "",
        "subject": null,
        "specVersion": "1.0",
        "source": "http://goparamore.io/",
        "topic": "apiservice.*",
        "timeStamp": "2026-06-18T14:28:06+00:00",
        "traceParent": "",
        "traceState": "",
        "type": {
            "value": "testMessage"
        },
        "workflowId": null
    },
    "body": {
        "bytes": "eyJpZCI6IjAxOWVkYjIxLWNmMDktN2YyYi05YTdlLWU0ZTgyZTkxODc0MyIsInNwZWN2ZXJzaW9uIjoiMS4wIiwic291cmNlIjoiaHR0cDovL2dvcGFyYW1vcmUuaW8iLCJ0eXBlIjoidGVzdE1lc3NhZ2UiLCJkYXRhY29udGVudHR5cGUiOiJhcHBsaWNhdGlvbi9qc29uIiwiZGF0YXNjaGVtYSI6bnVsbCwic3ViamVjdCI6bnVsbCwidGltZSI6IjIwMjYtMDYtMThUMTQ6Mjg6MDYuNjcxMTYzKzAwOjAwIiwiZGF0YSI6eyJjb3JyZWxhdGlvbklkIjpudWxsLCJpZCI6IjAxOWVkYjIxLWNmMDktN2YyYi05YTdlLWU0ZTgyZTkxODc0MyJ9fQ==",
        "memory": "eyJpZCI6IjAxOWVkYjIxLWNmMDktN2YyYi05YTdlLWU0ZTgyZTkxODc0MyIsInNwZWN2ZXJzaW9uIjoiMS4wIiwic291cmNlIjoiaHR0cDovL2dvcGFyYW1vcmUuaW8iLCJ0eXBlIjoidGVzdE1lc3NhZ2UiLCJkYXRhY29udGVudHR5cGUiOiJhcHBsaWNhdGlvbi9qc29uIiwiZGF0YXNjaGVtYSI6bnVsbCwic3ViamVjdCI6bnVsbCwidGltZSI6IjIwMjYtMDYtMThUMTQ6Mjg6MDYuNjcxMTYzKzAwOjAwIiwiZGF0YSI6eyJjb3JyZWxhdGlvbklkIjpudWxsLCJpZCI6IjAxOWVkYjIxLWNmMDktN2YyYi05YTdlLWU0ZTgyZTkxODc0MyJ9fQ==",
        "contentType": {
            "boundary": null,
            "charSet": "utf-8",
            "mediaType": "application/json",
            "name": null,
            "parameters": [
                {
                    "key": "charset",
                    "value": "utf-8"
                }
            ]
        },
        "characterEncoding": "UTF8",
        "value": "{\"id\":\"019edb21-cf09-7f2b-9a7e-e4e82e918743\",\"specversion\":\"1.0\",\"source\":\"http://goparamore.io\",\"type\":\"testMessage\",\"datacontenttype\":\"application/json\",\"dataschema\":null,\"subject\":null,\"time\":\"2026-06-18T14:28:06.671163+00:00\",\"data\":{\"correlationId\":null,\"id\":\"019edb21-cf09-7f2b-9a7e-e4e82e918743\"}}"
    },
    "isEmpty": false,
    "id": "019edb21-cf09-7f2b-9a7e-e4e82e918743"
}

Am I on the right track? Or is there some system in Brighter and/or OpenTelemetry so that the {routingKey} process span that Brighter creates will be correlated with the trace referenced in the header?

Forgive my ignorance, I'm new to Sentry and OpenTelemetry, and Brighter for that matter.

P.S.

I have one more question about the traces produced by Brighter's provided instrumentation. I keep getting traces named {routingKey} receive. Is this related to Brighter polling the inbox, or something like that? The spans are all around 2.55s long.

[dssldavidmorgan]

Currently, this is working to correlate the handler activity with the parent trace in the message, but it's leaving orphan {routingKey} process traces. I suppose I need to inject some behaviour earlier in Brighter's processing, before it creates the process span, so that it will be created as a child of the trace parent.

using Paramore.Brighter;
using SentryTest.Messages;
using System.Diagnostics;

namespace SentryTest.Receiver;

public class TestMessageHandler : RequestHandlerAsync<TestMessage>
{
    private readonly ILogger<TestMessageHandler> _logger;
    private static readonly ActivitySource _activitySource = new(typeof(TestMessageHandler).Assembly.GetName().Name!);

    public TestMessageHandler(
        ILogger<TestMessageHandler> logger)
    {
        _logger = logger;
    }

    public override async Task<TestMessage> HandleAsync(TestMessage command, CancellationToken cancellationToken = default)
    {
        var traceParent = Context?.OriginatingMessage?.Header.Bag["traceparent"] as string;

        using var activity = _activitySource.StartActivity(
            $"{nameof(TestMessageHandler)}.{nameof(HandleAsync)}",
            ActivityKind.Consumer,
            traceParent);

        if (activity is not null)
        {
            Context?.Span = activity;
        }

        _logger.LogError("Errorororoororor");

        return await base.HandleAsync(command, cancellationToken).ConfigureAwait(ContinueOnCapturedContext);
    }
}

[dssldavidmorgan]

I think there are essentially two things going on here:

1. Paramore.Brighter.Extensions.DependencyInjection.ServiceCollectionExtensions.Tracer is looking for a registered BrighterTracer to pass into the IAmAnOutboxProducerMediator it builds on line 737, but in other places it's looking for an IAmABrighterTracer, and that's what is registered in Paramore.Brighter.Extensions.Diagnostics.BrighterTracerBuilderExtensions.AddBrighterInstrumentation#17. I think this may be an error, but it can be gotten around by registering one's own BrighterTracer instance.

2. Sentry has a "sentry-trace" key instead of a "traceparent" key which Message.PropogateContext doesn't understand. Maybe I need to set a different DefaultTextMapPropagator.

If I do that custom BrighterTracer registration and avoid using Sentry then the trace propagation works.

I was able to solve it with a propagator like this:

public class TextMapPropagator : SentryPropagator
{
    public override void Inject<T>(PropagationContext context, T carrier, Action<T, string, string> setter)
    {
        if (carrier is Message)
        {
            var traceId = context.ActivityContext.TraceId.ToHexString();
            var spanId = context.ActivityContext.SpanId.ToHexString();
            var flags = context.ActivityContext.TraceFlags.HasFlag(ActivityTraceFlags.Recorded) ? "01" : "00";

            setter(carrier, "traceparent", $"00-{traceId}-{spanId}-{flags}");
        }
        else
        {
            base.Inject(context, carrier, setter);
        }
    }
}

So the solution is:

1. Register a tracer as both its class and interface:

var tracer = new BrighterTracer(TimeProvider.System);
builder.Services.AddSingleton<BrighterTracer>(tracer);
builder.Services.AddSingleton<IAmABrighterTracer>(tracer);

2. For Sentry, use the propagator above for compatibility with Brighter.