GlobalOpenTelemetry returns no-op when using Agent

[dreedyman]

I've created an extension where I implement a AutoConfigurationCustomizerProvider to setup OpenTelemetry SDK. The extension is embedded into the agent. All works as planned. However, when I attach the agent to a JVM, and from within that app I invoke GlobalOpenTelemetry.get(), I get a no-op instance. I had expected to obtain the configured SDK that my extension had created.

I've followed the discussion here but must be missing something. Any suggestions welcome.

[laurit]

By any chance are you using otel.instrumentation.common.default-enabled=false? Firstly try running without extension does it work then? If it does then it must be something that your extension is doing.

[dreedyman]

@laurit That is indeed the case, I have set otel.instrumentation.common.default-enabled=false to turn off everything, then selectively turn on what instrumentations I need. After removing that system property, the GlobalOpenTelemetry.get() returns as expected.

Is there another option to do what I'm intending to do? I'd rather not have all instrumentations available, just those that teams need, and still be able to have GlobalOpenTelemetry.get() available. Thank you!

[laurit]

GlobalOpenTelemetry.get() is instrumented to expose the OpenTelemetry instance configured by the agent. You have disabled that instrumentation.

[dreedyman]

@laurit As documented here, this property is used to disable all default auto instrumentation, and then we can selectively re-enable individual instrumentation. It shouldn't turn the agent off. The agent still instruments for the instrumentations that have been enabled using otel.instrumentation.[name].enabled=true.

Are you saying that if I want GlobalOpenTelemetry.get() to return as expected I have to enable all instrumentations? Doesn't this contradict the advice given that control what instrumentations are enabled, to assist with the performance and reduction of possible duplicate spans?

[laurit]

Are you saying that if I want GlobalOpenTelemetry.get() to return as expected I have to enable all instrumentations?

You have to enable only the instrumentation that instruments GlobalOpenTelemetry.get(). Disabling instrumentations by default and selectively enabling some isn't a great idea precisely because for average user it is hard to assess which instrumentations they need and which instrumentations depend on other instrumentations.

[dreedyman]

You have to enable only the instrumentation that instruments GlobalOpenTelemetry.get().

Aha. Perhaps if it were pointed out either online or in this discussion that GlobalOpenTelemetry.get() is not only created using the logic explained here, but also controlled by the otel.instrumentation.opentelemetry-api.enable property (I guess you did, I just didn't pick it up). Did I get that right?

Disabling instrumentations by default and selectively enabling some isn't a great idea precisely because for average user > it is hard to assess which instrumentations they need and which instrumentations depend on other instrumentations.

Well, this somewhat contradicts the documented approach on suppressing and enabling the instrumentations that have been identified as being required.

And if that's all correct, then we can close this, and thank you for the assistance.

[trask]

see (and vote!) for #7201