fix(opentelemetry): sync resource name with OTel span name on SetName by link04 · Pull Request #4887 · DataDog/dd-trace-go

link04 · 2026-06-12T03:38:46Z

What does this PR do?

Makes the OTel bridge's SetName also update the Datadog resource name (not just the operation name), so the span name exported over OTLP follows a later SetName call.

Motivation

tracer.Start seeds the DD resource from the initial OTel span name, but SetName only updated the operation name — the resource (and thus the OTLP-exported span name) kept the stale value. Instrumentations like otelhttp create the span before routing ("GET") and call SetName with the low-cardinality route afterwards ("GET /users/{id}"); the exported OTLP span name must follow to match the pure OpenTelemetry SDK.

Independent of DD_TRACE_OTEL_SEMANTICS_ENABLED.

Testing

Adds TestSpanSetNameUpdatesResource. Full ddtrace/opentelemetry suite passes.

APMAPI-2016

🤖 Generated with Claude Code

codecov · 2026-06-12T03:41:28Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.67%. Comparing base (08a41d6) to head (4e2bd38).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

Files with missing lines	Coverage Δ
ddtrace/opentelemetry/span.go	`89.88% <100.00%> (-2.81%)`	⬇️

... and 289 files with indirect coverage changes

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

datadog-datadog-prod-us1-2 · 2026-06-12T03:43:00Z

Tests

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 62.99% (+4.30%)

_{This comment will be updated automatically if new data arrives.

🔗 Commit SHA: 4e2bd38 | Docs | Datadog PR Page | Give us feedback!}

pr-commenter · 2026-06-12T04:04:12Z

Benchmarks

Benchmark execution time: 2026-06-12 21:20:19

Comparing candidate commit 4e2bd38 in PR branch maximo/otel-bridge-setname-resource with baseline commit 08a41d6 in branch main.

Found 0 performance improvements and 3 performance regressions! Performance is the same for 294 metrics, 2 unstable metrics, 1 flaky benchmarks without significant changes.

Explanation

This is an A/B test comparing a candidate commit's performance against that of a baseline commit. Performance changes are noted in the tables below as:

🟩 = significantly better candidate vs. baseline
🟥 = significantly worse candidate vs. baseline

We compute a confidence interval (CI) over the relative difference of means between metrics from the candidate and baseline commits, considering the baseline as the reference.

If the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD), the change is considered significant.

Feel free to reach out to #apm-benchmarking-platform on Slack if you have any questions.

More details about the CI and significant changes

You can imagine this CI as a range of values that is likely to contain the true difference of means between the candidate and baseline commits.

CIs of the difference of means are often centered around 0%, because often changes are not that big:

---------------------------------(------|---^--------)-------------------------------->
                              -0.6%    0%  0.3%     +1.2%
                                 |          |        |
         lower bound of the CI --'          |        |
sample mean (center of the CI) -------------'        |
         upper bound of the CI ----------------------'

As described above, a change is considered significant if the CI is entirely outside the configured SIGNIFICANT_IMPACT_THRESHOLD (or the deprecated UNCONFIDENCE_THRESHOLD).

For instance, for an execution time metric, this confidence interval indicates a significantly worse performance:

----------------------------------------|---------|---(---------^---------)---------->
                                       0%        1%  1.3%      2.2%      3.1%
                                                  |   |         |         |
       significant impact threshold --------------'   |         |         |
                      lower bound of CI --------------'         |         |
       sample mean (center of the CI) --------------------------'         |
                      upper bound of CI ----------------------------------'

scenario:BenchmarkOTelApiWithCustomTags/otel_api

🟥 allocated_mem [+462 bytes; +475 bytes] or [+10.742%; +11.039%]
🟥 allocations [+6; +6] or [+15.000%; +15.000%]
🟥 execution_time [+923.254ns; +1019.746ns] or [+13.795%; +15.237%]

Known flaky benchmarks

These benchmarks are marked as flaky and will not trigger a failure. Modify FLAKY_BENCHMARKS_REGEX to control which benchmarks are marked as flaky.

Known flaky benchmarks without significant changes:

scenario:BenchmarkOTLPTraceWriterFlush

zacharycmontoya · 2026-06-12T19:52:47Z

For maintainers, this same type of issue was discovered in dd-trace-js where the OtelSpan.updateName API was also incorrectly setting the DD span operation name, where it should be updating the DD span resource name: DataDog/dd-trace-js#8864

zacharycmontoya · 2026-06-12T19:53:34Z

 	s.attributes[ext.SpanName] = strings.ToLower(name)
+	// Keep the resource in sync with the renamed span: Start seeds the resource from the
+	// initial name, and the OTLP exporter emits the resource as the span's name field.
+	s.attributes[ext.ResourceName] = name


Yep this change looks correct. In the linked dd-trace-js PR, we replaced the previous "set the operation name" instruction with this new "set the resource name" instruction. Can we do the same here in dd-trace-go?

zacharycmontoya

LGTM. Let's see if we can replace the previous "operation name" update entirely since operation name is a DD-only concept

…name on SetName tracer.Start seeds the DD resource from the initial OTel span name, but SetName only updated the operation name — so the resource (and therefore the span name exported over OTLP) kept the stale value. Instrumentations such as otelhttp create the span before routing ("GET") and call SetName with the low-cardinality route afterwards ("GET /users/{id}"); the exported OTLP span name must follow. SetName now updates the resource name only. The operation name is a Datadog-only concept derived from the span's semantics, so it is no longer set from the OTel span name (matching the dd-trace-js change). Fixes the span name diverging from the pure OpenTelemetry SDK over OTLP. Independent of DD_TRACE_OTEL_SEMANTICS_ENABLED. APMAPI-2016 Co-Authored-By: Claude Opus 4.8 <[email protected]>

link04 · 2026-06-15T17:56:08Z

@codex review

Copilot

Pull request overview

This PR updates the OpenTelemetry bridge span renaming behavior so that calling Span.SetName(...) updates the underlying Datadog resource name (which is what ultimately maps to the OTLP-exported span name), rather than changing the Datadog operation name.

Changes:

Update (*span).SetName to write ext.ResourceName (resource) instead of ext.SpanName (operation).
Adjust existing TestSpanSetName expectations to validate resource rename behavior and unchanged DD-computed operation name.
Add a new regression test covering a common HTTP route-renaming scenario (e.g., "GET" → "GET /users/{id}").

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
ddtrace/opentelemetry/span.go	Make `SetName` update Datadog resource name to keep OTLP span name in sync with OTel renames.
ddtrace/opentelemetry/span_test.go	Update assertions for the new mapping and add coverage for post-start span renames.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

chatgpt-codex-connector · 2026-06-15T17:59:38Z

Codex Review: Didn't find any major issues. 🎉

Reviewed commit: 4e2bd38bf2

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

Open a pull request for review
Mark a draft as ready
Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

link04 · 2026-06-16T15:03:14Z

Superseded by #4889. Per the team discussion (and matching the dd-trace-js decision), the SetName → resource-name change is a breaking change for a minor release — it shifts RED metrics — so it's now gated behind DD_TRACE_OTEL_SEMANTICS_ENABLED in #4889 rather than changing the default. The change (and Zach's "replace the operation-name update entirely" feedback) has been moved there, gated and tested in both flag states. Closing in favor of #4889.

) ### What does this PR do? Adds an opt-in `DD_TRACE_OTEL_SEMANTICS_ENABLED` that aligns OTLP-exported spans (and the OTel bridge) with the pure OpenTelemetry SDK by suppressing Datadog-specific attributes and stopping DD-convention remaps. Mirrors dd-trace-py #18495 and libdatadog #2091. ### Behavior when `DD_TRACE_OTEL_SEMANTICS_ENABLED=true` - Omit `operation.name`, `resource.name`, `span.type` (DD-only span attributes) - Omit `error.message`/`type`/`stack`/`handling_stack` from the span (they live on the exception span event for Error Tracking) - Omit `span.kind` (already carried by the first-class OTLP `SpanKind` field) - Keep `http.response.status_code` under its OTel key instead of remapping to the legacy `http.status_code` string tag - The OTel bridge no longer interprets Datadog reserved tags (`operation.name`, `analytics.event`, `http.response.status_code`) in `SetAttributes` — they pass through as provided - `SetName` updates the Datadog **resource** (which the OTLP exporter emits as the span name) instead of the DD-only **operation name** Default (flag off) behavior is unchanged. ### Why `SetName` is gated here (moved from #4887) Changing `SetName` to update the resource is the correct OTel-aligned behavior, but doing it unconditionally is a breaking change: it shifts both the operation name **and** resource name, which changes users' RED metrics. Per team discussion (matching the dd-trace-js decision), this belongs behind the semantics flag rather than as a default change in a minor release. This supersedes #4887. ### Performance The flag is read **once** per export batch in `otlpTraceWriter.add()` and resolved **once** at provider creation for the bridge (cached on the `oteltracer`), then threaded as a parameter / read as a field — no per-span/per-attribute global config lookup. ### Testing `TestConvertSpanAttributesOtelSemantics`, `TestRemapStatusCodeOtelSemantics`, `TestToReservedAttributesOtelSemantics`, and `TestSpanSetNameUpdatesResourceOtelSemantics` (flag on) plus the existing `TestSpanSetName` (flag off, legacy operation-name behavior). Full `ddtrace/tracer`, `ddtrace/opentelemetry`, and `internal/config` suites pass. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: maximo.bautista <[email protected]>

zacharycmontoya reviewed Jun 12, 2026

View reviewed changes

zacharycmontoya approved these changes Jun 12, 2026

View reviewed changes

link04 force-pushed the maximo/otel-bridge-setname-resource branch from f892dc2 to 58392f8 Compare June 12, 2026 20:46

link04 force-pushed the maximo/otel-bridge-setname-resource branch from 58392f8 to 4e2bd38 Compare June 12, 2026 20:53

link04 requested a review from Copilot June 15, 2026 17:55

Copilot started reviewing on behalf of link04 June 15, 2026 17:56 View session

Copilot AI reviewed Jun 15, 2026

View reviewed changes

link04 mentioned this pull request Jun 16, 2026

feat(tracer): add DD_TRACE_OTEL_SEMANTICS_ENABLED for OTLP export #4889

Merged

link04 closed this Jun 16, 2026

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

fix(opentelemetry): sync resource name with OTel span name on SetName#4887

fix(opentelemetry): sync resource name with OTel span name on SetName#4887
link04 wants to merge 1 commit into
mainfrom
maximo/otel-bridge-setname-resource

link04 commented Jun 12, 2026

Uh oh!

codecov Bot commented Jun 12, 2026 •

edited

Loading

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Jun 12, 2026 •

edited

Loading

Uh oh!

pr-commenter Bot commented Jun 12, 2026 •

edited

Loading

Explanation

More details about the CI and significant changes

Known flaky benchmarks

Uh oh!

zacharycmontoya commented Jun 12, 2026

Uh oh!

zacharycmontoya Jun 12, 2026

Uh oh!

zacharycmontoya left a comment

Uh oh!

link04 commented Jun 15, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

chatgpt-codex-connector Bot commented Jun 15, 2026

Uh oh!

link04 commented Jun 16, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Uh oh!

Conversation

link04 commented Jun 12, 2026

What does this PR do?

Motivation

Testing

Uh oh!

codecov Bot commented Jun 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Jun 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

pr-commenter Bot commented Jun 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Benchmarks

Explanation

More details about the CI and significant changes

scenario:BenchmarkOTelApiWithCustomTags/otel_api

Known flaky benchmarks

Uh oh!

zacharycmontoya commented Jun 12, 2026

Uh oh!

zacharycmontoya Jun 12, 2026

Choose a reason for hiding this comment

Uh oh!

zacharycmontoya left a comment

Choose a reason for hiding this comment

Uh oh!

link04 commented Jun 15, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

chatgpt-codex-connector Bot commented Jun 15, 2026

Uh oh!

link04 commented Jun 16, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

codecov Bot commented Jun 12, 2026 •

edited

Loading

datadog-datadog-prod-us1-2 Bot commented Jun 12, 2026 •

edited

Loading

pr-commenter Bot commented Jun 12, 2026 •

edited

Loading