support otlp export format by mtoffl01 · Pull Request #4522 · DataDog/dd-trace-go

mtoffl01 · 2026-03-10T15:22:54Z

What does this PR do?

Motivation

Reviewer's Checklist

Changed code has unit tests for its functionality at or near 100% coverage.
System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
There is a benchmark for any new code, or changes to existing code.
If this interacts with the agent in a new way, a system test has been added.
New code is free of linting errors. You can check this by running make lint locally.
New code doesn't break existing tests. You can check this by running make test locally.
Add an appropriate team label so this PR gets put in the right place for the release notes.
All generated files are up to date. You can check this by running make generate locally.
Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild. Make sure all nested modules are up to date by running make fix-modules locally.

Unsure? Have a question? Request a review!

… interface

…an conversion logic into its own file

datadog-datadog-prod-us1 · 2026-03-10T15:29:45Z

⚠️ Tests

✨ Fix all issues with BitsAI or with Cursor

⚠️ Warnings

🧪 5 Tests failed

TestStartupLog from github.com/DataDog/dd-trace-go/v2/ddtrace/tracer (Datadog) (Fix with Cursor)
Failed

=== RUN   TestStartupLog
--- FAIL: TestStartupLog (0.14s)
TestStartupLog/basic from github.com/DataDog/dd-trace-go/v2/ddtrace/tracer (Datadog) (Fix with Cursor)
Failed

=== RUN   TestStartupLog/basic
    log_test.go:39: 
        	Error Trace:	/home/runner/work/dd-trace-go/dd-trace-go/ddtrace/tracer/log_test.go:39
        	Test:       	TestStartupLog/basic
    --- FAIL: TestStartupLog/basic (0.01s)
TestStartupLog/configured from github.com/DataDog/dd-trace-go/v2/ddtrace/tracer (Datadog) (Fix with Cursor)
Failed

=== RUN   TestStartupLog/configured
    log_test.go:71: 
        	Error Trace:	/home/runner/work/dd-trace-go/dd-trace-go/ddtrace/tracer/log_test.go:71
        	Test:       	TestStartupLog/configured
    --- FAIL: TestStartupLog/configured (0.06s)
View all

ℹ️ Info

No other issues found (see more)

❄️ No new flaky tests detected

🎯 Code Coverage (details)
• Patch Coverage: 87.16%
• Overall Coverage: 59.52% (+0.28%)

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

🔗 Commit SHA: 8eea461 | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}

pr-commenter · 2026-03-10T15:48:41Z

Benchmarks

Benchmark execution time: 2026-03-13 15:30:11

Comparing candidate commit 8eea461 in PR branch mtoff/otlp-export with baseline commit 89047df in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 156 metrics, 8 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 ----------------------------------'

…s for these fields

…, replace interface{} with any

…on http client's Read()

codecov · 2026-03-11T20:36:14Z

Codecov Report

❌ Patch coverage is 89.78723% with 24 lines in your changes missing coverage. Please review.
✅ Project coverage is 60.39%. Comparing base (89047df) to head (3c9e4ec).
⚠️ Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
ddtrace/tracer/payload_otlp_convert.go	90.76%	9 Missing and 3 partials ⚠️
ddtrace/tracer/payload_otlp.go	82.75%	8 Missing and 2 partials ⚠️
ddtrace/tracer/otel_dd_mappings.go	77.77%	2 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
ddtrace/tracer/log.go	`87.09% <100.00%> (-4.12%)`	⬇️
ddtrace/tracer/option.go	`84.42% <100.00%> (-1.89%)`	⬇️
ddtrace/tracer/payload.go	`100.00% <ø> (ø)`
ddtrace/tracer/transport.go	`87.36% <ø> (-6.32%)`	⬇️
ddtrace/tracer/writer.go	`91.83% <100.00%> (-2.47%)`	⬇️
internal/agent.go	`73.91% <100.00%> (ø)`
ddtrace/tracer/otel_dd_mappings.go	`67.02% <77.77%> (-1.59%)`	⬇️
ddtrace/tracer/payload_otlp.go	`82.75% <82.75%> (ø)`
ddtrace/tracer/payload_otlp_convert.go	`90.76% <90.76%> (ø)`

... and 272 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.

…ers on otlp

github-actions · 2026-03-12T19:55:12Z

+	if raw == "" {
+		return headers
+	}
+	for _, pair := range strings.Split(raw, ",") {


🚫 [golangci] _{reported by reviewdog 🐶}
stringsseq: Ranging over SplitSeq is more efficient (modernize)

…d fix version and name fields on resource attributes

### Background This PR is part of an ongoing effort to support OTLP Traces Export Phase 1, documented [here](https://docs.google.com/document/d/1AsUrJxjJavLvSG33kUAJLYzGU8IYgrnf1SMbFDsuGmo/edit?tab=t.avgpmfl6f0c6#heading=h.jssp4de43yev). It contains some placeholder/no-op code (e.g. otlpTraceWriter) which will be implemented in follow-up PRs (e.g, #4522). ### What does this PR do? When OTLP export mode is enabled, the SDK must not use the Datadog Agent priority sampler, since there is no agent available to provide per-service sampling rates. This PR introduces a replacement fallback sampler for that mode. New type: `otelParentBasedAlwaysOnSampler` — implements the `parentbased_always_on` strategy ([ref](https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/#general-sdk-configuration)), which honors propagated sampling decisions from parent contexts, otherwise samples all traces at rate 1.0. User-configured rules take precedence over this fallback. New interface: `defaultSampler` — abstracts the fallback sampling strategy applied when no user-defined rules match a span. Both `prioritySampler` (agent mode) and `otelParentBasedAlwaysOnSampler` (OTLP mode) satisfy this interface, replacing the previous concrete `*prioritySampler` field on the tracer and ensuring the fallback is never nil. ### Motivation See Requirements: https://docs.google.com/document/d/1AsUrJxjJavLvSG33kUAJLYzGU8IYgrnf1SMbFDsuGmo/edit?tab=t.avgpmfl6f0c6#heading=h.nqkivnomx6oe ### Reviewer's Checklist  - [ ] Changed code has unit tests for its functionality at or near 100% coverage. - [ ] [System-Tests](https://github.com/DataDog/system-tests/) covering this feature have been added and enabled with the va.b.c-dev version tag. - [ ] There is a benchmark for any new code, or changes to existing code. - [ ] If this interacts with the agent in a new way, a system test has been added. - [ ] New code is free of linting errors. You can check this by running `make lint` locally. - [ ] New code doesn't break existing tests. You can check this by running `make test` locally. - [ ] Add an appropriate team label so this PR gets put in the right place for the release notes. - [ ] All generated files are up to date. You can check this by running `make generate` locally. - [ ] Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild. Make sure all nested modules are up to date by running `make fix-modules` locally. Unsure? Have a question? Request a review!

mtoffl01 added 4 commits March 6, 2026 16:38

implement bare minimum payload_otlp implementation to satisfy payload…

b036b89

… interface

Complete payloadOTLP satisfies payload interface; migrate DD -> OT sp…

2b14022

…an conversion logic into its own file

Support OTEL_TRACES_EXPORTER=otlp as traceProtocol

4f73bcf

Progress span conversion logic and add tests

28035f0

mtoffl01 added 8 commits March 10, 2026 14:24

better organize/format the convert file

5eb3695

progress implementation

5f51028

introduce tests

a4e47d1

implement Resource.Attributes and InstrumentationScope, plus add test…

8b530f9

…s for these fields

address lint issues: annotate with checklocksignore, fix import order…

bf1e333

…, replace interface{} with any

make payloadOTLP.count thread safe (atomic)

066555f

fix goimports in payload_otlp_test.go

fa850b9

fix direct access to p.count; replace with atomic

0d01847

kakkoyun self-requested a review March 11, 2026 10:11

mtoffl01 added 6 commits March 11, 2026 15:26

Support the layers of endpoint configuration, plus tests

75d340f

Replace Content-Type header in OTLP export case, and test

bc7894d

return -1 for payloadOTLP.size() to enable chunked transfer encoding …

1b9add4

…on http client's Read()

only read sampling rates from agent if not traceProtocolOTLP

3db9145

move buildResource helper into convert file

f8ff321

fix imports

2a64cdc

mtoffl01 added 4 commits March 12, 2026 12:35

fix OTLP ENDPOINT configs -- do not modify agentURL

ef34c95

FOR TESTING: add otlp and trace url info to startup log

3c9e4ec

Fix Content-Length header for chunked encoding and never send dd head…

38ebdfd

…ers on otlp

Implement OTLP_HEADERS

a176f81

github-actions Bot reviewed Mar 12, 2026

View reviewed changes

implement cachedOTLPResource in order to build Resource only once, an…

8eea461

…d fix version and name fields on resource attributes

mtoffl01 mentioned this pull request Mar 19, 2026

feat(otel): Implement parentbased_always_on in otlp mode #4567

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mtoffl01 closed this Mar 24, 2026

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support otlp export format#4522

support otlp export format#4522
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mtoffl01 commented Mar 10, 2026

What does this PR do?

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