Helper class not sharing because of 2 class loaders

[srinivas-bitla]

Hello,

I am creating a custom extension for otel java instrumentation agent following the instructions here https://github.com/open-telemetry/opentelemetry-java-instrumentation/tree/main/examples/extension. I have

1. CustomInstrumentationModule extends InstrumentationModule
2. CustomInstrumentation implements TypeInstrumentation
3. CustomAdvice
4. CustomSampler extends io.opentelemetry.sdk.trace.samplers.Sampler
5. A helper class named CustomLogRecorder, which is used by CustomSampler and CustomAdvice.

What I find is that, CustomLogRecorder is loaded twice by 2 different class loaders. CustomSampler is loading it using otel class loader and InstrumentationModule is loading it again using a different class loader. Because of this I am unable to share the static data between CustomSampler and CustomAdvice. Is it possible to load CustomLogRecorder by only otel class loader in both cases?

[laurit]

Is it possible to load CustomLogRecorder by only otel class loader in both cases?

Currently no, advice code runs inside your application, it does not see the agent classes. You could solve this by placing an api in the boot loader that is visible to both the application and the agent. Note that we have some plans for reworking how advice works so sharing data between agent and advice code may become easier in future versions.

[srinivas-bitla]

Placing API in the boot loader means placing the extension jar or needed classes in the boot class path, which is not a decent hack. Can distro solve this problem?