@WithSpan annotation doesn't seem to work?

[stevensim226]

Hello there,
From what I read in this documentation there is a feature to open a a span by just using an annotation.

My code is as follows:

Span span = tracer.spanBuilder("ping").startSpan();
printTrace();
span.end();

with the method printTrace() as follows

@WithSpan(value = "printTrace")
public void printTrace() {
    System.out.println("Hello World!");
}

And from what I am using now (JaegerExporter) it only shows the ping span, but the printTrace span is nowhere to be found.
I have also added the java agent for automatic instrumentation (even though I don't think this is required for using the annotation @WithSpan)

Is there something that I forgot to set?

[kenfinnigan]

Is the opentelemetry-extension-annotations dependency present?

[kenfinnigan]

The Javadoc mentions the need for an implementation to process the annotation: https://www.javadoc.io/doc/io.opentelemetry/opentelemetry-contrib-auto-annotations/latest/index.html

Also, you mention you are using manual instrumentation but the @WithSpan is documented in the automatic instrumentation docs. It sounds like that's where the mismatch is which is why it's not being exported

[jkwatson]

At the moment the only thing that provides an implementation of the annotation is the auto instrumentation agent.

We have an open feature request to provide alternative ways of using it, but nothing has been implemented yet.

[stevensim226]

I see @jkwatson ,
Though I now already understood that it seems the annotation is only usable if automatic instrumentation is enabled and this may not be the appropriate place to ask this question, but what's the purpose of @WithSpan if we already enabled automatic instrumentation?

Or CMIIW but is it like the automatic instrumentation's purpose is to solely provide the tracer instance?

[kenfinnigan]

The intention is to allow addition span creation for internal methods, as you had done, that automatic instrumentation wouldn't add by default

[ghost]

@stevensim226 this is the feature request / issue that @jkwatson mentioned about processing the annotations without autoinstrumentation agent: #3035