Add withParent option to annotation @WithSpan

[xiepuhuan]

Related to #1036

[xiepuhuan]

The smoke test of grpc failed. Because I modified the @WithSpan annotation of instrumentation-annotations, and the grpc smoke test image uses @WithSpan, I need to rely on the new smoke test grpc image version.
What should I do? @trask help me

[laurit]

The smoke test of grpc failed. Because I modified the @WithSpan annotation of instrumentation-annotations, and the grpc smoke test image uses @WithSpan, I need to rely on the new smoke test grpc image version. What should I do? @trask help me

You got it wrong. The test is failing because after your changes the instrumentation does not work any more for old version of the @WithSpan annotation that does not have the withParent attribute. This is a bug in your PR.

[xiepuhuan]

The smoke test of grpc failed. Because I modified the @WithSpan annotation of instrumentation-annotations, and the grpc smoke test image uses @WithSpan, I need to rely on the new smoke test grpc image version. What should I do? @trask help me

You got it wrong. The test is failing because after your changes the instrumentation does not work any more for old version of the @WithSpan annotation that does not have the withParent attribute. This is a bug in your PR.

@laurit Thank you for your reply. I want to use reflection to determine whether the withParent method exists to fix this bug and achieve backward compatibility. Do you have any suggestions for this?

[trask]

I kind of like the name proposed in #5837: noParent()

at first I thought I liked something like newTrace(), but concerned people will overuse it thinking that if they don't then it won't create a span if there's no existing trace

cc @open-telemetry/java-instrumentation-approvers any thoughts on naming?

[xiepuhuan]

root() or rootSpan()?

[trask]

yeah, what I was trying to avoid is that people may think using root() or rootSpan() is the only way to create a root span, when creating a root span is already the default if there's not an existing parent span already

some other options...

• withoutParent()
• breakFromParent()
• ignoreParent()

[trask]

another option

• inheritContext() default true

which points to it being more than just lack of parent span

[xiepuhuan]

another option

• inheritContext() default true

which points to it being more than just lack of parent span

I think this is good.