Low allocation OTLP marshalers for OtlpJsonLogging{Signal}Exporters

[vasantteja]

Resolves #6474

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.01%. Comparing base (68fcd44) to head (e1fc21e).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #7616   +/-   ##
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  Coverage     90.01%   90.01%           
- Complexity     7090     7096    +6     
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  Files           803      803           
  Lines         21443    21461   +18     
  Branches       2092     2092           
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+ Hits          19301    19319   +18     
  Misses         1477     1477           
  Partials        665      665           

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[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: vasantteja / name: Teja (8314743, b1df8b0, bcabdef, 09915eb, e1fc21e, 16d0dd9, af4af1f, 37ac611, eccd941, 2264a41, c55f375, 8aa19ed, e44adfe, 2748933)
• ✅ login: hilmarf / name: Hilmar Falkenberg (8aa19ed)

[vasantteja]

• ✅ login: vasantteja / name: Teja (b1df8b0, eccd941, 2264a41, af4af1f, 8314743, c55f375, 2748933, 16d0dd9, 09915eb, bcabdef, e44adfe, 37ac611, 8aa19ed)
• ❌ - login: @hilmarf / name: Hilmar Falkenberg . The commit (8aa19ed) is not authorized under a signed CLA. Please click here to be authorized. For further assistance with EasyCLA, please submit a support request ticket.

@hilmarf Can you please sign this so that I can include your suggestion?

[jkwatson]

Seems reasonable to me. Thanks!

[jkwatson]

@hilmarf Are you able to sign the CLA, so we can accept your contribution to this PR?

[zeitlinger]

I'll also do a review.

[zeitlinger]

Thanks a lot for the PR 😄

• setMemoryMode and boolean useLowAllocation do the same thing - so we should stick to setMemoryMode
• setWrapperJsonObject and useLowAllocation is unrelated - I don't understand why it was renamed
• OtlpJsonLogging{Signal}Exporter is kind of deprecated
  • If you want to have more options, such as low allocation, you can use OtlpStdout{Signal}Exporter
  • e.g. OtlpStdoutLogRecordExporter.builder().setMemoryMode(MemoryMode.REUSABLE_DATA).build()

In total, I don't understand what is possible with this PR that was not possible before.

[jkwatson]

• setWrapperJsonObject and useLowAllocation is unrelated - I don't understand why it was renamed

"setWrapperJsonObject" doens't mean anything to the end user. The new API is a request for low allocation, so it makes sense to name the boolean after what the user wants, rather than an implementation detail. I'm not sure about the internal renames and if it makes sense to have them as well.

[vasantteja]

Thanks a lot for the PR 😄

• setMemoryMode and boolean useLowAllocation do the same thing - so we should stick to setMemoryMode

• setWrapperJsonObject and useLowAllocation is unrelated - I don't understand why it was renamed

• OtlpJsonLogging{Signal}Exporter is kind of deprecated

  • If you want to have more options, such as low allocation, you can use OtlpStdout{Signal}Exporter
  • e.g. OtlpStdoutLogRecordExporter.builder().setMemoryMode(MemoryMode.REUSABLE_DATA).build()

In total, I don't understand what is possible with this PR that was not possible before.

Thanks for the feedback! You're absolutely right - I'm planning to close this PR and I believe we can close the related issue.

Why:

1. Functionality already exists: Users can already get low allocation with OtlpStdoutMetricExporter.builder().setMemoryMode(MemoryMode.REUSABLE_DATA).build()

2. API duplication: setMemoryMode and boolean useLowAllocation do the same thing, creating confusion

3. Architectural mismatch: OtlpJsonLogging*Exporter are legacy compatibility wrappers. New features belong in the modern OtlpStdout*Exporter APIs.

4. Conflated concerns: JSON wrapper format and memory allocation are separate concepts that shouldn't be tied together

The right solution:

Direct users to the existing, better API:

OtlpStdoutMetricExporter.builder().setMemoryMode(MemoryMode.REUSABLE_DATA).build()

This keeps the architecture clean and avoids unnecessary API complexity. Thanks for the thoughtful review! Let me know your thoughts.

CC: @zeitlinger, @jkwatson