[ygree]

What Does This Do

Prevents closed-channel failures on the final Netty server response write from marking otherwise successful spans as errors.

Suppression applies only to ClosedChannelException and Netty’s StacklessClosedChannelException without an underlying cause. Existing application errors, HTTP error statuses, wrapped failures, and interruption-related exceptions remain reportable.

Motivation

#11941 began observing asynchronous response-write failures. #12295 excluded native broken-pipe and connection-reset failures, but left closed-channel client disconnects counted as trace errors even when the response status remained HTTP 200.

This extends that handling to the client-disconnect case reproduced by the regression test.

Additional Notes

• Adds a real client-disconnect reproduction and protective test cases.

• Validated against baseline and latest Netty dependencies.

• Closed-channel exceptions do not identify who closed the connection, so suppression is restricted to the terminal response-write callback.

• Backport to 1.68.x once merged

Contributor Checklist

• Format the title according to the contribution guidelines
• Assign the type: and (comp: or inst:) labels in addition to any other useful labels
• Avoid using close, fix, or any linking keywords when referencing an issue
  Use solves instead, and assign the PR milestone to the issue
• Update the CODEOWNERS file on source file addition, migration, or deletion
• Update public documentation with any new configuration flags or behaviors
• Once approved, use merge queue to merge the PR

Jira ticket: APMS-20898

[datadog-official]

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 68.82% (+9.31%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 3cb1161 | Docs | Give us feedback!}

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	14.84 s	14.75 s	[-0.5%; +1.7%] (no difference)
startup:insecure-bank:tracing:Agent	13.59 s	13.71 s	[-1.7%; -0.0%] (maybe better)
startup:petclinic:appsec:Agent	17.75 s	17.57 s	[+0.0%; +2.0%] (maybe worse)
startup:petclinic:iast:Agent	17.53 s	17.67 s	[-1.8%; +0.2%] (no difference)
startup:petclinic:profiling:Agent	17.62 s	17.09 s	[+1.9%; +4.4%] (significantly worse)
startup:petclinic:sca:Agent	17.78 s	17.66 s	[-0.5%; +1.9%] (no difference)
startup:petclinic:tracing:Agent	16.30 s	16.31 s	[-6.0%; +5.9%] (unstable)

Commit: 3cb11616 · CI Pipeline · Benchmarking Platform UI

---

Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

[ygree]

@codex review

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-29T16:18:31.629071Z	3cb1161	Draft marked ready
🔒 Security Review	✅ Completed 2026-10-29T16:19:57.667589Z	3cb1161	Draft marked ready

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[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Swish!

Reviewed commit: 3cb116161a

ℹ️ About Codex in GitHub

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[chatgpt-codex-connector]

🛡️ Codex Security Review · Automatically triggered

Security review completed. No security issues were found in this pull request.

Reviewed commit: 3cb116161a

View security finding report

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ℹ️ About Codex security reviews in GitHub

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Once complete, Codex will leave suggestions, or a comment if no findings are found.

[datadog-official]

More details

Suppression is restricted to cause-free closed-channel failures on terminal response writes, preserving existing span errors, HTTP error statuses, and other exception types. Static review identified no actionable regression.

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[matthieulabbe]

Tested 1.69.0-SNAPSHOT~3cb116161a in our environment and it worked as expected.

Thanks for the quick fix!