feat(otlp): add instrumentation scope metadata

[bengl]

What does this PR do?

Adds OTLP instrumentation scope metadata to the current trace exporter path.

The trace mapper now copies instrumentation_scope_name and instrumentation_scope_version from OtlpResourceInfo into ScopeSpans.scope. TraceExporterBuilder gets a setter for OTLP trace scope metadata, stores those values in OtlpTraceConfig, and the exporter copies them into each OTLP trace OtlpResourceInfo before mapping.

The C FFI exporter config also exposes the same scope setter so non-Rust tracer callers can configure the scope when they enable OTLP export.

Motivation

dd-trace-js native OTLP trace export emitted scope: {} through @datadog/libdatadog@0.16.0. Its Platform OTLP integration test expects the Datadog tracer scope (name: dd-trace-js) and a tracer version.

Additional Notes

This branch was ported from the old v37-based patch onto current main; it is one commit ahead of main and no longer carries the release-line diff that made the earlier draft conflicting.

DataDog/libdatadog-nodejs#173 currently pins this PR head (8cd68ab922fb7aade0f089ccfc91291d874673af) only as a temporary unreleased dependency. Once libdatadog publishes an official release/tag containing this change, libdatadog-nodejs should move to that release/tag.

How to test the change?

• cargo +nightly-2026-02-08 fmt --all -- --check
• cargo test -p libdd-trace-utils otlp_encoder::mapper --lib (26 pass)
• cargo test -p libdd-data-pipeline trace_exporter::builder::tests::test_new --lib (1 pass)
• cargo test -p libdd-data-pipeline-ffi config_otlp_instrumentation_scope_test --lib (2 pass)
• cargo check -p libdd-trace-utils
• cargo check -p libdd-data-pipeline
• cargo check -p libdd-data-pipeline-ffi
• cargo test -p libdd-data-pipeline-ffi trace_exporter --lib (28 pass)
• Reviewer: LibdatadogReviewFeedbackFix approved with no findings

[datadog-official]

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 81.44%
• Overall Coverage: 74.44% (+0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 8cd68ab | Docs | Datadog PR Page | Give us feedback!}

[pr-commenter]

Benchmarks

Comparison

Benchmark execution time: 2026-07-14 17:55:18

Comparing candidate commit 8cd68ab in PR branch bengl/otlp-scope-metadata-v37 with baseline commit 56dab85 in branch main.

Found 1 performance improvements and 0 performance regressions! Performance is the same for 138 metrics, 0 unstable metrics.

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:tags/replace_trace_tags

• 🟩 execution_time [-120.091ns; -100.555ns] or [-4.818%; -4.034%]

Benchmark execution time: 2026-07-14 17:53:43

Comparing candidate commit 8cd68ab in PR branch bengl/otlp-scope-metadata-v37 with baseline commit 56dab85 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 75 metrics, 10 unstable metrics.

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 ----------------------------------'

Candidate

Omitted due to size.

Baseline

Omitted due to size.

[dd-octo-sts]

Artifact Size Benchmark Report

aarch64-alpine-linux-musl

Artifact	Baseline	Commit	Change
/aarch64-alpine-linux-musl/lib/libdatadog_profiling.a	86.15 MB	86.16 MB	+.01% (+13.27 KB) 🔍
/aarch64-alpine-linux-musl/lib/libdatadog_profiling.so	7.88 MB	7.88 MB	0% (0 B) 👌

aarch64-unknown-linux-gnu

Artifact	Baseline	Commit	Change
/aarch64-unknown-linux-gnu/lib/libdatadog_profiling.a	97.40 MB	97.41 MB	+.01% (+15.86 KB) 🔍
/aarch64-unknown-linux-gnu/lib/libdatadog_profiling.so	10.62 MB	10.62 MB	+0% (+288 B) 👌

libdatadog-x64-windows

Artifact	Baseline	Commit	Change
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.dll	25.54 MB	25.55 MB	+.02% (+6.50 KB) 🔍
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.lib	88.44 KB	88.85 KB	+.46% (+424 B) 🔍
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.pdb	185.33 MB	185.33 MB	0% (0 B) 👌
/libdatadog-x64-windows/debug/static/datadog_profiling_ffi.lib	957.25 MB	957.28 MB	+0% (+26.53 KB) 👌
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.dll	8.35 MB	8.36 MB	+.07% (+6.00 KB) 🔍
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.lib	88.44 KB	88.85 KB	+.46% (+424 B) 🔍
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.pdb	24.72 MB	24.73 MB	+.03% (+8.00 KB) 🔍
/libdatadog-x64-windows/release/static/datadog_profiling_ffi.lib	49.21 MB	49.23 MB	+.03% (+16.84 KB) 🔍

libdatadog-x86-windows

Artifact	Baseline	Commit	Change
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.dll	22.19 MB	22.20 MB	+.02% (+5.50 KB) 🔍
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.lib	89.82 KB	90.24 KB	+.46% (+430 B) 🔍
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.pdb	189.78 MB	189.78 MB	0% (0 B) 👌
/libdatadog-x86-windows/debug/static/datadog_profiling_ffi.lib	945.93 MB	945.96 MB	+0% (+24.15 KB) 👌
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.dll	6.46 MB	6.46 MB	+.03% (+2.50 KB) 🔍
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.lib	89.82 KB	90.24 KB	+.46% (+430 B) 🔍
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.pdb	26.54 MB	26.55 MB	+.02% (+8.00 KB) 🔍
/libdatadog-x86-windows/release/static/datadog_profiling_ffi.lib	46.82 MB	46.84 MB	+.02% (+13.99 KB) 🔍

x86_64-alpine-linux-musl

Artifact	Baseline	Commit	Change
/x86_64-alpine-linux-musl/lib/libdatadog_profiling.a	76.96 MB	76.98 MB	+.01% (+15.37 KB) 🔍
/x86_64-alpine-linux-musl/lib/libdatadog_profiling.so	8.81 MB	8.81 MB	+.04% (+4.00 KB) 🔍

x86_64-unknown-linux-gnu

Artifact	Baseline	Commit	Change
/x86_64-unknown-linux-gnu/lib/libdatadog_profiling.a	92.37 MB	92.39 MB	+.01% (+15.78 KB) 🔍
/x86_64-unknown-linux-gnu/lib/libdatadog_profiling.so	10.72 MB	10.72 MB	+.03% (+4.17 KB) 🔍

[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: 76a2c25992

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[ekump]

could you add test coverage for the new fields in the builder? You can probably just add them to test_new()

[ekump]

These fields should live within otlp_config