[feat][pip] PIP-446: Support Native OpenTelemetry Tracing in Pulsar Java Client

[Technoboy-]

Motivation

Support Native OpenTelemetry Tracing in Pulsar Java client

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[github-actions]

@Technoboy- Please add the following content to your PR description and select a checkbox:

- [ ] `doc` <!-- Your PR contains doc changes -->
- [ ] `doc-required` <!-- Your PR changes impact docs and you will update later -->
- [ ] `doc-not-needed` <!-- Your PR changes do not impact docs -->
- [ ] `doc-complete` <!-- Docs have been already added -->

[lhotari]

One additional point to consider in the design is the behavior when sampling is configured (I believe that's the default) and a specific span isn't recorded at all. In those cases, an implementation can choose to reduce the overhead by omitting certain calls to the OTel tracing API.
This is explained in the Span IsRecording and Sampling documentation.
Although a span isn't sampled, it's still necessary to create child spans to propagate the span context to downstream, so optimizations based on span.isRecording() might not be very useful in the end.

I also noticed that the current Otel API that we have in Pulsar doesn't contain isRecording. We should also make sure to upgrade to latest stable versions of Otel libraries when implementing this PIP.

[lhotari]

Does the scope of this work include publishing semantic conventions for Pulsar directly to OpenTelemetry project? For example contribution custom attributes to https://github.com/open-telemetry/semantic-conventions/blob/main/model/messaging/registry.yaml / https://github.com/open-telemetry/semantic-conventions/blob/main/model/messaging/spans.yaml and contributing the specification documentation?

[Technoboy-]

I think so, whatever please help review the implementation to avoid missing something.