opentelemetry-otlp how to name service: OTLPResourceNoAttributes

[clux]

Currently, all my traces show up as top level OTLPResourceNoAttributes:

Is there a way to inject the service name with opentelemetry-otlp like in opentelemetry-jaeger?

[TommyCpp]

There isn't a service name concept in OTEL. So the convention here(and in opentelemetry-jaeger) is to use service.name resource to represent the service name. But it depends on the backend to correctly identify the service.name resource.

[clux]

Hm, ok. Thank you. I should probably open a bug against Tempo in that case, as service.name does not work there.

Btw, in golang the way I see this is done is by naming the tracer:
https://github.com/joe-elliott/tempo-otel-example/blob/492add7ad56769c0b0bbc80499f42dcb8cde8131/main.go#L47-L50
which gets picked up by Tempo.

[TommyCpp]

Btw, in golang the way I see this is done is by naming the tracer:
https://github.com/joe-elliott/tempo-otel-example/blob/492add7ad56769c0b0bbc80499f42dcb8cde8131/main.go#L47-L50
which gets picked up by Tempo.

Actually, that is the instrument library name, which will appear as a tag otlp.instrumentation.library.name in Jaeger. The service name is setup here https://github.com/joe-elliott/tempo-otel-example/blob/492add7ad56769c0b0bbc80499f42dcb8cde8131/main.go#L115-L119. You should see the service name as demo-service instead of demo-app.

So I think Tempo does check the service.name. Mind share an example of how do you set up the service.name resource in Rust?

[clux]

Oh, yes, you are right, sorry, I do see demo-service.

The way I did it in rust was to set the fields with #[instrument]:

#[instrument(skip(ctx), fields(traceID, service.name = "foo-controller"))]
async fn reconcile(foo: Foo, ctx: Context<Data>) -> Result<ReconcilerAction, Error> {
    Span::current().record("traceID", &field::display(&telemetry::get_trace_id()));

which shows up on the interface, but as a tag rather than the service name:

[TommyCpp]

Usually, resources will be set when init the tracer provider. You can refer here to see how to do it

[clux]

Ahhh, it's a Resource. Thank you.

Added:

.with_trace_config(opentelemetry::sdk::trace::config().with_resource(
    opentelemetry::sdk::Resource::new(vec![opentelemetry::KeyValue::new("service.name", "foo-controller")]),
))

and it worked.

[TommyCpp]

Good to know. Since this was defined in spec, we do have a const value for service.name. You can find it here

opentelemetry-rust/opentelemetry-semantic-conventions/src/resource.rs

Line 27 in e9595b6

pub const SERVICE_NAME: Key = Key::from_static_str("service.name");