Skip to content

feat(stats)!: implement additional metric tags in libdd-trace-stats#2170

Draft
duncanpharvey wants to merge 1 commit into
mainfrom
duncan-harvey/libdd-trace-stats-additional-metric-tags
Draft

feat(stats)!: implement additional metric tags in libdd-trace-stats#2170
duncanpharvey wants to merge 1 commit into
mainfrom
duncan-harvey/libdd-trace-stats-additional-metric-tags

Conversation

@duncanpharvey

@duncanpharvey duncanpharvey commented Jun 26, 2026

Copy link
Copy Markdown
Contributor

What does this PR do?

  • Add additional metric tags to the stats aggregation key. For each configured key, the matching span meta tag is included in the key and populates ClientGroupedStats.additional_metric_tags.
  • Limit the number of keys for additional_metric_tags to 4, not configurable.
  • Limit the number of distinct aggregation entries per bucket that carry additional metric tags to 100 by default, configurable via additional_metric_tags_max_entries. Once exceeded, new entries have their tag values masked to tracer_blocked_value.
  • Limit the maximum length of individual additional_metric_tags values to 200 characters, not configurable. Values exceeding this are replaced with tracer_blocked_value.

Motivation

Allow Serverless Compatibility Layer to send additional metric tags on trace stats. DataDog/serverless-components#140 to follow.

https://datadoghq.atlassian.net/browse/SVLS-8787

Additional Notes

Implementing this change in place of #1815.

How to test the change?

Unit tests

@datadog-datadog-prod-us1-2

datadog-datadog-prod-us1-2 Bot commented Jun 26, 2026

Copy link
Copy Markdown

Tests

🎉 All green!

🧪 All tests passed
❄️ No new flaky tests detected

🎯 Code Coverage (details)
Patch Coverage: 97.92%
Overall Coverage: 74.60% (+0.23%)

This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 42e3296 | Docs | Datadog PR Page | Give us feedback!

@github-actions

github-actions Bot commented Jun 26, 2026

Copy link
Copy Markdown
Contributor

📚 Documentation Check Results

⚠️ 3026 documentation warning(s) found

📦 libdd-data-pipeline - 1204 warning(s)

📦 libdd-trace-protobuf - 227 warning(s)

📦 libdd-trace-stats - 864 warning(s)

📦 libdd-trace-utils - 731 warning(s)


Updated: 2026-07-06 18:15:50 UTC | Commit: 4507b4b | missing-docs job results

@github-actions

Copy link
Copy Markdown
Contributor

Clippy Allow Annotation Report

Comparing clippy allow annotations between branches:

  • Base Branch: origin/main
  • PR Branch: origin/duncan-harvey/libdd-trace-stats-additional-metric-tags

Summary by Rule

Rule Base Branch PR Branch Change
unwrap_used 1 1 No change (0%)
Total 1 1 No change (0%)

Annotation Counts by File

File Base Branch PR Branch Change
libdd-trace-stats/src/stats_exporter.rs 1 1 No change (0%)

Annotation Stats by Crate

Crate Base Branch PR Branch Change
clippy-annotation-reporter 5 5 No change (0%)
datadog-ffe-ffi 1 1 No change (0%)
datadog-ipc 22 22 No change (0%)
datadog-live-debugger 4 4 No change (0%)
datadog-live-debugger-ffi 10 10 No change (0%)
datadog-profiling-replayer 4 4 No change (0%)
datadog-sidecar 45 45 No change (0%)
libdd-common 13 13 No change (0%)
libdd-common-ffi 12 12 No change (0%)
libdd-data-pipeline 6 6 No change (0%)
libdd-ddsketch 2 2 No change (0%)
libdd-dogstatsd-client 1 1 No change (0%)
libdd-profiling 13 13 No change (0%)
libdd-remote-config 3 3 No change (0%)
libdd-telemetry 20 20 No change (0%)
libdd-tinybytes 4 4 No change (0%)
libdd-trace-normalization 2 2 No change (0%)
libdd-trace-obfuscation 3 3 No change (0%)
libdd-trace-stats 1 1 No change (0%)
libdd-trace-utils 11 11 No change (0%)
Total 182 182 No change (0%)

About This Report

This report tracks Clippy allow annotations for specific rules, showing how they've changed in this PR. Decreasing the number of these annotations generally improves code quality.

@github-actions

github-actions Bot commented Jun 26, 2026

Copy link
Copy Markdown
Contributor

🔒 Cargo Deny Results

⚠️ 4 issue(s) found, showing only errors (advisories, bans, sources)

📦 libdd-data-pipeline - 2 error(s)

Show output
error[unsound]: Rand is unsound with a custom logger using `rand::rng()`
    ┌─ /home/runner/work/libdatadog/libdatadog/Cargo.lock:218:1
    │
218 │ rand 0.8.5 registry+https://github.com/rust-lang/crates.io-index
    │ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ unsound advisory detected
    │
    ├ ID: RUSTSEC-2026-0097
    ├ Advisory: https://rustsec.org/advisories/RUSTSEC-2026-0097
    ├ It has been reported (by @lopopolo) that the `rand` library is [unsound](https://rust-lang.github.io/unsafe-code-guidelines/glossary.html#soundness-of-code--of-a-library) (i.e. that safe code using the public API can cause Undefined Behaviour) when all the following conditions are met:
      
      - The `log` and `thread_rng` features are enabled
      - A [custom logger](https://docs.rs/log/latest/log/#implementing-a-logger) is defined
      - The custom logger accesses `rand::rng()` (previously `rand::thread_rng()`) and calls any `TryRng` (previously `RngCore`) methods on `ThreadRng`
      - The `ThreadRng` (attempts to) reseed while called from the custom logger (this happens every 64 kB of generated data)
      - Trace-level logging is enabled or warn-level logging is enabled and the random source (the `getrandom` crate) is unable to provide a new seed
      
      `TryRng` (previously `RngCore`) methods for `ThreadRng` use `unsafe` code to cast `*mut BlockRng<ReseedingCore>` to `&mut BlockRng<ReseedingCore>`. When all the above conditions are met this results in an aliased mutable reference, violating the Stacked Borrows rules. Miri is able to detect this violation in sample code. Since construction of [aliased mutable references is Undefined Behaviour](https://doc.rust-lang.org/stable/nomicon/references.html), the behaviour of optimized builds is hard to predict.
    ├ Announcement: https://github.com/rust-random/rand/pull/1763
    ├ Solution: Upgrade to >=0.10.1 OR <0.10.0, >=0.9.3 OR <0.9.0, >=0.8.6 (try `cargo update -p rand`)
    ├ rand v0.8.5
      ├── libdd-common v5.0.0
      │   ├── libdd-capabilities-impl v2.0.0
      │   │   ├── libdd-data-pipeline v6.0.0
      │   │   ├── libdd-shared-runtime v1.0.0
      │   │   │   ├── libdd-data-pipeline v6.0.0 (*)
      │   │   │   ├── libdd-telemetry v5.0.1
      │   │   │   │   ├── libdd-data-pipeline v6.0.0 (*)
      │   │   │   │   └── libdd-trace-stats v5.0.0
      │   │   │   │       └── libdd-data-pipeline v6.0.0 (*)
      │   │   │   └── libdd-trace-stats v5.0.0 (*)
      │   │   ├── libdd-trace-stats v5.0.0 (*)
      │   │   └── libdd-trace-utils v8.0.0
      │   │       ├── libdd-data-pipeline v6.0.0 (*)
      │   │       ├── libdd-trace-obfuscation v4.0.0
      │   │       │   └── libdd-trace-stats v5.0.0 (*)
      │   │       ├── libdd-trace-stats v5.0.0 (*)
      │   │       └── (dev) libdd-trace-utils v8.0.0 (*)
      │   ├── libdd-data-pipeline v6.0.0 (*)
      │   ├── libdd-dogstatsd-client v3.0.0
      │   │   ├── libdd-data-pipeline v6.0.0 (*)
      │   │   └── libdd-trace-stats v5.0.0 (*)
      │   ├── libdd-shared-runtime v1.0.0 (*)
      │   ├── libdd-telemetry v5.0.1 (*)
      │   ├── libdd-trace-obfuscation v4.0.0 (*)
      │   ├── libdd-trace-stats v5.0.0 (*)
      │   └── libdd-trace-utils v8.0.0 (*)
      ├── (dev) libdd-data-pipeline v6.0.0 (*)
      ├── (dev) libdd-ddsketch v1.0.1
      │   ├── libdd-data-pipeline v6.0.0 (*)
      │   ├── libdd-telemetry v5.0.1 (*)
      │   └── libdd-trace-stats v5.0.0 (*)
      ├── (dev) libdd-trace-normalization v2.0.0
      │   ├── libdd-data-pipeline v6.0.0 (*)
      │   └── libdd-trace-utils v8.0.0 (*)
      ├── (dev) libdd-trace-stats v5.0.0 (*)
      ├── libdd-trace-utils v8.0.0 (*)
      └── proptest v1.5.0
          └── (dev) libdd-tinybytes v1.1.1
              ├── libdd-data-pipeline v6.0.0 (*)
              ├── (dev) libdd-tinybytes v1.1.1 (*)
              └── libdd-trace-utils v8.0.0 (*)

error[vulnerability]: Denial of Service via Stack Exhaustion
    ┌─ /home/runner/work/libdatadog/libdatadog/Cargo.lock:287:1
    │
287 │ time 0.3.41 registry+https://github.com/rust-lang/crates.io-index
    │ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ security vulnerability detected
    │
    ├ ID: RUSTSEC-2026-0009
    ├ Advisory: https://rustsec.org/advisories/RUSTSEC-2026-0009
    ├ ## Impact
      
      When user-provided input is provided to any type that parses with the RFC 2822 format, a denial of
      service attack via stack exhaustion is possible. The attack relies on formally deprecated and
      rarely-used features that are part of the RFC 2822 format used in a malicious manner. Ordinary,
      non-malicious input will never encounter this scenario.
      
      ## Patches
      
      A limit to the depth of recursion was added in v0.3.47. From this version, an error will be returned
      rather than exhausting the stack.
      
      ## Workarounds
      
      Limiting the length of user input is the simplest way to avoid stack exhaustion, as the amount of
      the stack consumed would be at most a factor of the length of the input.
    ├ Announcement: https://github.com/time-rs/time/blob/main/CHANGELOG.md#0347-2026-02-05
    ├ Solution: Upgrade to >=0.3.47 (try `cargo update -p time`)
    ├ time v0.3.41
      └── tracing-appender v0.2.3
          └── libdd-log v1.0.0
              └── (dev) libdd-data-pipeline v6.0.0

advisories FAILED, bans ok, sources ok

📦 libdd-trace-protobuf - ✅ No issues

📦 libdd-trace-stats - 1 error(s)

Show output
error[unsound]: Rand is unsound with a custom logger using `rand::rng()`
    ┌─ /home/runner/work/libdatadog/libdatadog/Cargo.lock:198:1
    │
198 │ rand 0.8.5 registry+https://github.com/rust-lang/crates.io-index
    │ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ unsound advisory detected
    │
    ├ ID: RUSTSEC-2026-0097
    ├ Advisory: https://rustsec.org/advisories/RUSTSEC-2026-0097
    ├ It has been reported (by @lopopolo) that the `rand` library is [unsound](https://rust-lang.github.io/unsafe-code-guidelines/glossary.html#soundness-of-code--of-a-library) (i.e. that safe code using the public API can cause Undefined Behaviour) when all the following conditions are met:
      
      - The `log` and `thread_rng` features are enabled
      - A [custom logger](https://docs.rs/log/latest/log/#implementing-a-logger) is defined
      - The custom logger accesses `rand::rng()` (previously `rand::thread_rng()`) and calls any `TryRng` (previously `RngCore`) methods on `ThreadRng`
      - The `ThreadRng` (attempts to) reseed while called from the custom logger (this happens every 64 kB of generated data)
      - Trace-level logging is enabled or warn-level logging is enabled and the random source (the `getrandom` crate) is unable to provide a new seed
      
      `TryRng` (previously `RngCore`) methods for `ThreadRng` use `unsafe` code to cast `*mut BlockRng<ReseedingCore>` to `&mut BlockRng<ReseedingCore>`. When all the above conditions are met this results in an aliased mutable reference, violating the Stacked Borrows rules. Miri is able to detect this violation in sample code. Since construction of [aliased mutable references is Undefined Behaviour](https://doc.rust-lang.org/stable/nomicon/references.html), the behaviour of optimized builds is hard to predict.
    ├ Announcement: https://github.com/rust-random/rand/pull/1763
    ├ Solution: Upgrade to >=0.10.1 OR <0.10.0, >=0.9.3 OR <0.9.0, >=0.8.6 (try `cargo update -p rand`)
    ├ rand v0.8.5
      ├── libdd-common v5.0.0
      │   ├── libdd-capabilities-impl v2.0.0
      │   │   ├── libdd-shared-runtime v1.0.0
      │   │   │   ├── libdd-telemetry v5.0.1
      │   │   │   │   └── libdd-trace-stats v5.0.0
      │   │   │   └── libdd-trace-stats v5.0.0 (*)
      │   │   ├── libdd-trace-stats v5.0.0 (*)
      │   │   └── libdd-trace-utils v8.0.0
      │   │       ├── libdd-trace-obfuscation v4.0.0
      │   │       │   └── libdd-trace-stats v5.0.0 (*)
      │   │       ├── libdd-trace-stats v5.0.0 (*)
      │   │       └── (dev) libdd-trace-utils v8.0.0 (*)
      │   ├── libdd-dogstatsd-client v3.0.0
      │   │   └── libdd-trace-stats v5.0.0 (*)
      │   ├── libdd-shared-runtime v1.0.0 (*)
      │   ├── libdd-telemetry v5.0.1 (*)
      │   ├── libdd-trace-obfuscation v4.0.0 (*)
      │   ├── libdd-trace-stats v5.0.0 (*)
      │   └── libdd-trace-utils v8.0.0 (*)
      ├── (dev) libdd-ddsketch v1.0.1
      │   ├── libdd-telemetry v5.0.1 (*)
      │   └── libdd-trace-stats v5.0.0 (*)
      ├── (dev) libdd-trace-normalization v2.0.0
      │   └── libdd-trace-utils v8.0.0 (*)
      ├── (dev) libdd-trace-stats v5.0.0 (*)
      ├── libdd-trace-utils v8.0.0 (*)
      └── proptest v1.5.0
          └── (dev) libdd-tinybytes v1.1.1
              ├── (dev) libdd-tinybytes v1.1.1 (*)
              └── libdd-trace-utils v8.0.0 (*)

advisories FAILED, bans ok, sources ok

📦 libdd-trace-utils - 1 error(s)

Show output
error[unsound]: Rand is unsound with a custom logger using `rand::rng()`
    ┌─ /home/runner/work/libdatadog/libdatadog/Cargo.lock:181:1
    │
181 │ rand 0.8.5 registry+https://github.com/rust-lang/crates.io-index
    │ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ unsound advisory detected
    │
    ├ ID: RUSTSEC-2026-0097
    ├ Advisory: https://rustsec.org/advisories/RUSTSEC-2026-0097
    ├ It has been reported (by @lopopolo) that the `rand` library is [unsound](https://rust-lang.github.io/unsafe-code-guidelines/glossary.html#soundness-of-code--of-a-library) (i.e. that safe code using the public API can cause Undefined Behaviour) when all the following conditions are met:
      
      - The `log` and `thread_rng` features are enabled
      - A [custom logger](https://docs.rs/log/latest/log/#implementing-a-logger) is defined
      - The custom logger accesses `rand::rng()` (previously `rand::thread_rng()`) and calls any `TryRng` (previously `RngCore`) methods on `ThreadRng`
      - The `ThreadRng` (attempts to) reseed while called from the custom logger (this happens every 64 kB of generated data)
      - Trace-level logging is enabled or warn-level logging is enabled and the random source (the `getrandom` crate) is unable to provide a new seed
      
      `TryRng` (previously `RngCore`) methods for `ThreadRng` use `unsafe` code to cast `*mut BlockRng<ReseedingCore>` to `&mut BlockRng<ReseedingCore>`. When all the above conditions are met this results in an aliased mutable reference, violating the Stacked Borrows rules. Miri is able to detect this violation in sample code. Since construction of [aliased mutable references is Undefined Behaviour](https://doc.rust-lang.org/stable/nomicon/references.html), the behaviour of optimized builds is hard to predict.
    ├ Announcement: https://github.com/rust-random/rand/pull/1763
    ├ Solution: Upgrade to >=0.10.1 OR <0.10.0, >=0.9.3 OR <0.9.0, >=0.8.6 (try `cargo update -p rand`)
    ├ rand v0.8.5
      ├── (dev) libdd-common v5.0.0
      │   ├── libdd-capabilities-impl v2.0.0
      │   │   └── libdd-trace-utils v8.0.0
      │   │       └── (dev) libdd-trace-utils v8.0.0 (*)
      │   └── libdd-trace-utils v8.0.0 (*)
      ├── (dev) libdd-trace-normalization v2.0.0
      │   └── libdd-trace-utils v8.0.0 (*)
      ├── libdd-trace-utils v8.0.0 (*)
      └── proptest v1.5.0
          └── (dev) libdd-tinybytes v1.1.1
              ├── (dev) libdd-tinybytes v1.1.1 (*)
              └── libdd-trace-utils v8.0.0 (*)

advisories FAILED, bans ok, sources ok

Updated: 2026-07-06 18:17:26 UTC | Commit: 4507b4b | dependency-check job results

@duncanpharvey duncanpharvey force-pushed the duncan-harvey/libdd-trace-stats-additional-metric-tags branch 2 times, most recently from c020593 to 82959f7 Compare June 29, 2026 14:47
@duncanpharvey duncanpharvey force-pushed the duncan-harvey/libdd-trace-stats-additional-metric-tags branch from 82959f7 to 9977516 Compare June 29, 2026 15:13
@dd-octo-sts

dd-octo-sts Bot commented Jun 29, 2026

Copy link
Copy Markdown
Contributor

Artifact Size Benchmark Report

aarch64-alpine-linux-musl
Artifact Baseline Commit Change
/aarch64-alpine-linux-musl/lib/libdatadog_profiling.a 85.91 MB 86.09 MB +.21% (+188.13 KB) 🔍
/aarch64-alpine-linux-musl/lib/libdatadog_profiling.so 7.88 MB 7.88 MB +0% (+48 B) 👌
aarch64-unknown-linux-gnu
Artifact Baseline Commit Change
/aarch64-unknown-linux-gnu/lib/libdatadog_profiling.a 97.11 MB 97.29 MB +.19% (+188.99 KB) 🔍
/aarch64-unknown-linux-gnu/lib/libdatadog_profiling.so 10.61 MB 10.61 MB +.04% (+4.80 KB) 🔍
libdatadog-x64-windows
Artifact Baseline Commit Change
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.dll 25.46 MB 25.51 MB +.21% (+55.50 KB) 🔍
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.lib 88.44 KB 88.44 KB 0% (0 B) 👌
/libdatadog-x64-windows/debug/dynamic/datadog_profiling_ffi.pdb 184.60 MB 184.89 MB +.15% (+296.00 KB) 🔍
/libdatadog-x64-windows/debug/static/datadog_profiling_ffi.lib 946.34 MB 947.13 MB +.08% (+814.17 KB) 🔍
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.dll 8.32 MB 8.34 MB +.18% (+16.00 KB) 🔍
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.lib 88.44 KB 88.44 KB 0% (0 B) 👌
/libdatadog-x64-windows/release/dynamic/datadog_profiling_ffi.pdb 24.62 MB 24.68 MB +.25% (+64.00 KB) 🔍
/libdatadog-x64-windows/release/static/datadog_profiling_ffi.lib 49.04 MB 49.13 MB +.18% (+95.08 KB) 🔍
libdatadog-x86-windows
Artifact Baseline Commit Change
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.dll 22.06 MB 22.11 MB +.22% (+51.00 KB) 🔍
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.lib 89.82 KB 89.82 KB 0% (0 B) 👌
/libdatadog-x86-windows/debug/dynamic/datadog_profiling_ffi.pdb 188.62 MB 188.93 MB +.16% (+320.00 KB) 🔍
/libdatadog-x86-windows/debug/static/datadog_profiling_ffi.lib 935.31 MB 936.00 MB +.07% (+704.12 KB) 🔍
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.dll 6.43 MB 6.44 MB +.18% (+12.50 KB) 🔍
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.lib 89.82 KB 89.82 KB 0% (0 B) 👌
/libdatadog-x86-windows/release/dynamic/datadog_profiling_ffi.pdb 26.43 MB 26.48 MB +.20% (+56.00 KB) 🔍
/libdatadog-x86-windows/release/static/datadog_profiling_ffi.lib 46.65 MB 46.74 MB +.18% (+89.94 KB) 🔍
x86_64-alpine-linux-musl
Artifact Baseline Commit Change
/x86_64-alpine-linux-musl/lib/libdatadog_profiling.a 76.59 MB 76.75 MB +.20% (+162.03 KB) 🔍
/x86_64-alpine-linux-musl/lib/libdatadog_profiling.so 8.78 MB 8.79 MB +.17% (+16.06 KB) 🔍
x86_64-unknown-linux-gnu
Artifact Baseline Commit Change
/x86_64-unknown-linux-gnu/lib/libdatadog_profiling.a 92.11 MB 92.26 MB +.17% (+162.41 KB) 🔍
/x86_64-unknown-linux-gnu/lib/libdatadog_profiling.so 10.69 MB 10.71 MB +.21% (+23.77 KB) 🔍

@duncanpharvey duncanpharvey force-pushed the duncan-harvey/libdd-trace-stats-additional-metric-tags branch from fb6b20d to b3d13e5 Compare June 29, 2026 16:02
gh-worker-dd-mergequeue-cf854d Bot pushed a commit that referenced this pull request Jul 1, 2026
# What does this PR do?

- Update protobufs to be in sync with datadog-agent
  * `containerDebug`
  * `additional_metric_tags`
- Update `DATADOG_AGENT_TAG` for protobufs comparison to DataDog/datadog-agent@fdc29d4

# Motivation

Out of sync protobufs with datadog-agent. Needed for #2170.

# Additional Notes

<img width="788" height="301" alt="Screenshot 2026-06-29 at 3 03 21 PM" src="https://github.com/user-attachments/assets/ac605731-2338-4919-a078-1cb31de9b2d0" />

# How to test the change?

- Weekly test to compare protobufs to main: https://github.com/DataDog/libdatadog/actions/workflows/weekly-verify-proto-files.yml
- Per PR test to compare protobugs to specified commit: https://github.com/DataDog/libdatadog/actions/workflows/verify-proto-files.yml


Co-authored-by: duncan.harvey <duncan.harvey@datadoghq.com>
@duncanpharvey duncanpharvey force-pushed the duncan-harvey/libdd-trace-stats-additional-metric-tags branch from b3d13e5 to def0a56 Compare July 6, 2026 16:47
@github-actions github-actions Bot removed the ci-build label Jul 6, 2026
@duncanpharvey duncanpharvey force-pushed the duncan-harvey/libdd-trace-stats-additional-metric-tags branch from def0a56 to 42e3296 Compare July 6, 2026 18:13
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant