HDDS-13803. Client aware tracing

[sravani-revuri]

What changes were proposed in this pull request?

The Ozone client needs the flexibility to either initiate a new span or continue an existing application-level trace by creating a child span. Currently, if ozone.tracing.enabled is false, all tracing is suppressed. A specific scenario arises when the Ozone client should only trace if it's explicitly enabled to continue an application's existing trace.

• When ozone.tracing.enabled is True:
  • The client uses the standard Ozone-initialized tracer (existing behavior).
• When ozone.tracing.enabled is False:
  • If application-aware is True and an active span exists: The client will create child spans using the application’s GlobalOpenTelemetry context. This allows Ozone operations to appear as children of the application's spans.
  • If no active span exists: No spans are created (standalone tracing remains off).
  • If application-aware is False: No spans are created regardless of the application context.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-13803

How was this patch tested?

Written unit tests and existing tests.

[sravani-revuri]

@sumitagrawl could you please review this.

[sreejasahithi]

Thanks @sravani-revuri for working on this.

[yandrey321]

there are way too many flags that control tracing behavior, can we simplify them and have no more than 2 control switches. Also we need to make sure that documentation describes behavior of these switches.

[sravani-revuri]

there are way too many flags that control tracing behavior, can we simplify them and have no more than 2 control switches.

Thanks for the feedback @yandrey321 ! After consideration, it might be better to stick with separate configs for now. Keeping one for enabling tracing would leave another one for trace sampling ,span sampling and endpoint configuration. Combining these would make it hard to understand and use.

Also we need to make sure that documentation describes behavior of these switches.

I have improved description for the configs to ensure their functionality is explained.

Please let me know if you have any suggestions to improve this regarding the configs!

[adoroszlai]

@sravani-revuri We could replace the two boolean config properties with ozone.tracing.mode enum of { OFF, CLIENT, FULL } (feel free to improve these names), default to CLIENT. We just need to set FULL if ozone.tracing.enabled=true, for compatibility.

[sravani-revuri]

@adoroszlai , @yandrey321 , @sumitagrawl cloud you please review these changes.