[codedbyadiiii]

Resolves #8831

Summary

Adds an opt-in mechanism for exporters to signal their supported export concurrency.

Changes

• Adds getConcurrencyLimit() to span, log, and metric exporter interfaces.
• Preserves serialized export behavior by default.
• Adds bounded concurrent export execution to:
  • BatchSpanProcessor
  • BatchLogRecordProcessor
  • PeriodicMetricReader
• Uses caller-runs backpressure when exporter capacity is exhausted.
• Ensures in-flight exports complete during flush and shutdown.
• Adds regression coverage for concurrent span exports.
• Updates generated API-diff files.

Testing

• ./gradlew :sdk:trace:test :sdk:logs:test :sdk:metrics:test
• ./gradlew :sdk:trace:jApiCmp :sdk:logs:jApiCmp :sdk:metrics:jApiCmp

[otelbot]

⚠️ API changes detected — additional maintainer review required

@jack-berg @jkwatson

This PR modifies the public API surface area of the following module(s):

• opentelemetry-sdk-logs
• opentelemetry-sdk-metrics
• opentelemetry-sdk-trace

Please review the changes in docs/apidiffs/current_vs_latest/ carefully before approving.

[opentelemetry-pr-dashboard]

Pull request dashboard status

Waiting on the author · refreshed 2026-10-22 13:46 UTC

Investigate required status check failures.

Status above doesn't look right?

• Just replied or pushed? Anything around or after the refresh time above may not be picked up yet — give it a few minutes.
• Should this be with reviewers? Comment /dashboard route:reviewers to route it to them.
• Anything wrong — including the routing? Report it with what you expected; it helps us improve the dashboard.

[codecov]

Codecov Report

❌ Patch coverage is 81.96721% with 22 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.40%. Comparing base (387f5c5) to head (db3118e).
⚠️ Report is 17 commits behind head on main.

Files with missing lines	Patch %	Lines
...metry/sdk/logs/export/BatchLogRecordProcessor.java	81.39%	8 Missing ⚠️
...telemetry/sdk/trace/export/BatchSpanProcessor.java	81.81%	8 Missing ⚠️
...metry/sdk/metrics/export/PeriodicMetricReader.java	81.25%	6 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8928      +/-   ##
============================================
- Coverage     90.65%   90.40%   -0.25%     
- Complexity    10887    10961      +74     
============================================
  Files          1015     1018       +3     
  Lines         29731    30103     +372     
  Branches       3876     3929      +53     
============================================
+ Hits          26953    27215     +262     
- Misses         1860     1938      +78     
- Partials        918      950      +32     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[jkwatson]

I'm ok with the API changes if Jack is.