service.name is not propagate to Jaeger using trace HTTP exporter

[marcmolla]

Description

It seems that service.name is not propagated to jaeger when we integrate open telemetry-go using otlptracehttp. At jaeger ui, we see OTLPResourceNoServiceName instead of the service name.

We checked the contexts of the service post to jaeger and the label "my_service" is not in the protobuf message.

Environment

• OS: Ubuntu 22.04.1 LTS
• Architecture: x86_64
• Go Version: 1.21
• opentelemetry-go version: v1.17.0

Steps To Reproduce

1. Add basic setup of HTTP exporter to the process:

        //traces
	client := otlptracehttp.NewClient(otlptracehttp.WithEndpoint("10.20.30.40:4318"), otlptracehttp.WithInsecure(), otlptracehttp.WithCompression(otlptracehttp.NoCompression))
	exp, err := otlptrace.New(context.Background(), client)
	if err != nil {
		log.Fatalf("creating OTLP trace exporter: %s", err.Error())
	}
	if err != nil {
		log.Fatal(err)
	}

	r, _ := resource.Merge(
		resource.Default(),
		resource.NewWithAttributes(
			semconv.SchemaURL,
			semconv.ServiceName("my_service"),
			semconv.ServiceVersion("v0.1"),
		),
	)

	tp := trace.NewTracerProvider(
		trace.WithBatcher(exp),
		trace.WithResource(r),
	)
	defer func() {
		if err := tp.Shutdown(context.Background()); err != nil {
			log.Fatal(err)
		}
	}()
	otel.SetTracerProvider(tp)

3. Setup jaeger-all-in-one
4. Check jaeger ui

Expected behavior

We expect that service.name is propagated to jaeger.

[dmathieu]

I've just tried booting the jaeger-all-in-one docker container on my machine, and running the otel-collector example: https://github.com/open-telemetry/opentelemetry-go/tree/main/example/otel-collector

I am properly getting the service name.

[marcmolla]

Yes, Otel-collector example also works for me

I will try to reproduce my issue using the otel-collector example as base....

thanks
Marc

[dmathieu]

If this is an issue between the collector and jaeger, shouldn't it be in the opentelemetry-collector repository ?

[marcmolla]

I manage to create a minimum example with the error:
main.txt

and this is the capture:

I solved the issue by changing the way I create the resource, using the one in the otel-collector example:

r, _ := resource.New(context.Background(),
           resource.WithAttributes(
	// the service name used to display traces in backends
	semconv.ServiceName("test-service"),
       ),
)

with this the service.name is propagated correctly to jaeger.

[dmathieu]

From your original example, it's possible/likely you have a resource merge error, giving you an empty resource.

Try the following:

r, err := resource.Merge(
	resource.Default(),
	resource.NewWithAttributes(
		semconv.SchemaURL,
		semconv.ServiceName("my_service"),
		semconv.ServiceVersion("v0.1"),
	),
)
if err != nil {
	log.Fatal(err)
}

Resource merges being problematic is a known issue. See #2341

With the example above, I'm getting resource merge errors if I use the latest library with semconv < 1.21.0.
It works fine if I use semconv 1.21.0.

[marcmolla]

yes, that is the issue:

2023/09/12 09:33:16 cannot merge resource due to conflicting Schema URL

The way of creating the resource is in the Getting Started doc, maybe it can be updated for avoiding this error:
https://opentelemetry.io/docs/instrumentation/go/getting-started/

thanks for your support!

[dmathieu]

The getting started doc documents the proper way of doing it. The problem here is the larger issue of resource versions which are hard to tackle/upgrade.
I'll close this issue. The broader problem is already tracked in #2341.

[pellared]

The way of creating the resource is in the Getting Started doc, maybe it can be updated for avoiding this error:
https://opentelemetry.io/docs/instrumentation/go/getting-started/

Already part of open-telemetry/opentelemetry.io#3235