test(trace-utils): add VecMap microbenchmarks#2126
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Add criterion microbenchmarks isolating `VecMap`, the linear-scan ordered map backing each span's `meta` and `metrics`. Covers insert, get (hit/miss), get_mut, contains_key, iter, dedup (with and without duplicates) and as_deduped_map (borrow vs. allocating path) across representative map sizes (4-64), using `BytesString` keys to match real span usage. Gated behind a new opt-in `bench-internals` feature (mirroring `libdd-sampling`) so the bench is not built by default. Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
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| # Opt-in switch for crate-internal microbenchmarks (e.g. `vec_map_bench`). Mirrors the | ||
| # `bench-internals` feature in `libdd-sampling`; the bench targets it via `required-features` so | ||
| # they are not built by default. Not intended for downstream consumers. | ||
| bench-internals = [] |
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A bit verbose, Opt-in switch for crate-internal microbenchmarksis sufficient
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Ah, I caught one instance but not this one 🙃
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Should we run the same bench cases on HashMaps to prove that VecMaps are more performance ?
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Good question! I thought about it, but I'm not sure criterion is the right tool for that, at least used naively. In particular it would report improvements or degradation for the stdlib hashmap for future PR, which is not very relevant for libdatadog devs.
Maybe what we could do is to make a criterion benchmark when we measure the difference or the ratio?
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(in particular my current goal for micro and macro benches is to be able to measure the evolution of perf: did a change made things better or worse, and how? I feel like comparing VecMap to HashMap is a bit different, and could be done as a one-off thing on the side)
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I agree, it doesn't even need to be committed even 👍🏽
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But you're right, we should do that. That could also gives us hint as to the range where VecMap should be preferred against HashMap or not. Is it like 1 to 50 elements and max duplicate ratio 10%, or is it actually fast until 250 elements and can tolerate 25% duplicates? Those are interesting question to answer.
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…ibdd-data-pipeline, libdd-li... (#2201) # Release proposal for libdd-capabilities-impl, libdd-common, libdd-data-pipeline, libdd-library-config, libdd-remote-config, libdd-sampling, libdd-telemetry, libdd-tinybytes, libdd-trace-utils and their dependencies This PR contains version bumps based on public API changes and commits since last release. ## libdd-capabilities **Next version:** `2.1.0` **Semver bump:** `minor` **Tag:** `libdd-capabilities-v2.1.0` ### Commits - feat(data-pipeline)!: add stdout log trace exporter (#2074) ## libdd-common **Next version:** `5.1.0` **Semver bump:** `minor` **Tag:** `libdd-common-v5.1.0` ### Commits - refactor(clippy): prefer core and alloc imports (#2196) - fix: update rustls-webpki to 0.103.13 (#2187) - fix: update anyhow for unsoundness (#2186) - feat(machine id): Add helpers in ddcommon to fetch the machine UUID l… (#2163) ## libdd-ddsketch **Next version:** `1.1.0` **Semver bump:** `minor` **Tag:** `libdd-ddsketch-v1.1.0` ### Commits - feat(data-pipeline)!: export client-computed span stats as OTLP trace metrics (#2067) - test(ddsketch): add microbenchmarks for add/encode/collapse (#2125) ## libdd-trace-protobuf **Next version:** `4.0.0` **Semver bump:** `major` **Tag:** `libdd-trace-protobuf-v4.0.0` ### Commits - chore!: update protobufs to be in sync with datadog-agent (#2180) - feat(stats)!: add whole key cardinality limit (#2158) - feat(remote-config)!: use the proto file from the agent (#2165) - feat(data-pipeline): OTLP HTTP/protobuf trace export (#2115) ## libdd-capabilities-impl **Next version:** `3.0.0` **Semver bump:** `major` **Tag:** `libdd-capabilities-impl-v3.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.1.0 → ^5.1.0 ### Commits - feat(data-pipeline)!: add stdout log trace exporter (#2074) ## libdd-library-config **Next version:** `3.0.0` **Semver bump:** `major` **Tag:** `libdd-library-config-v3.0.0` ###⚠️ major bump forced due to: - `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0 ### Commits - refactor(clippy): prefer core and alloc imports (#2196) - feat(library-config)!: caller-supplied threadlocal schema and extra process-context attributes (#2162) - fix(otel-thread-ctx): put the threadlocal attributes at the right place in the context (#2167) ## libdd-remote-config **Next version:** `2.0.0` **Semver bump:** `major` **Tag:** `libdd-remote-config-v2.0.0` ###⚠️ major bump forced due to: - `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0 ### Commits - refactor(libdd-remote-config)!: hide Target inner properties so they are not leaked (#2182) - feat(remote-config)!: use the proto file from the agent (#2165) - refactor(rc): reexport Endpoint and Tag common types (#2147) ## libdd-trace-normalization **Next version:** `3.0.0` **Semver bump:** `major` **Tag:** `libdd-trace-normalization-v3.0.0` ###⚠️ major bump forced due to: - `libdd-trace-protobuf`: ^3.0.1 → ^4.0.0 ### Commits - feat(data-pipeline)!: CSS Trace Filters (#1985) ## libdd-shared-runtime **Next version:** `2.0.0` **Semver bump:** `major` **Tag:** `libdd-shared-runtime-v2.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.1.0 → ^5.1.0 ### Commits - feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061) - feat(shared-runtime)!: use weak waker in trigger [APMSP-3371] (#2050) ## libdd-trace-utils **Next version:** `9.0.0` **Semver bump:** `major` **Tag:** `libdd-trace-utils-v9.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.2.0 → ^5.1.0 - `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0 ### Commits - ci(miri): skip slow miri tests (#2188) - chore!: update protobufs to be in sync with datadog-agent (#2180) - feat(data-pipeline): add agentless export (#2081) - feat(data-pipeline)!: add stdout log trace exporter (#2074) - feat(data-pipeline): OTLP HTTP/protobuf trace export (#2115) - feat(otlp)!: Export OTLP spans with attribute-level OTel compatibility (#2091) - test(trace-utils): add V05 msgpack decode microbenchmark (#2127) - feat(data-pipeline)!: export client-computed span stats as OTLP trace metrics (#2067) - test(trace-utils): add VecMap microbenchmarks (#2126) - chore(stats)!: submit p0 telemetry in stats (#2130) - refactor(change-buffer)!: replace slot index with span_id, fix segment isolation (#2105) - feat(data-pipeline)!: CSS Trace Filters (#1985) - feat(trace-exporter): add v1 span and its encoder (#2039) - fix(trace-utils): mark decoded span maps as deduped (#2110) - feat(trace-utils)!: change buffer implementation (#2055) - feat(native-spans)!: change buffer foundation (#2046) - refactor(span)!: use VecMap for `meta`, `metrics` and `meta_struct` for v04 spans (#2043) - test: fix timeouts on heavily contended scenarios (#2093) ## libdd-telemetry **Next version:** `6.0.0` **Semver bump:** `major` **Tag:** `libdd-telemetry-v6.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.2.0 → ^5.1.0 - `libdd-shared-runtime`: ^1.0.0 → ^2.0.0 ### Commits - ci(miri): skip slow miri tests (#2188) - refactor(libdd-telemetry)!: avoid leaking libdd-common types in the public API (#2152) - feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061) ## libdd-trace-obfuscation **Next version:** `5.0.0` **Semver bump:** `major` **Tag:** `libdd-trace-obfuscation-v5.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.2.0 → ^5.1.0 - `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0 - `libdd-trace-utils`: ^8.0.0 → ^9.0.0 ### Commits - refactor(clippy): prefer core and alloc imports (#2196) - ci(miri): skip slow miri tests (#2188) - fix: update anyhow for unsoundness (#2186) ## libdd-trace-stats **Next version:** `6.0.0` **Semver bump:** `major` **Tag:** `libdd-trace-stats-v6.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.2.0 → ^5.1.0 - `libdd-shared-runtime`: ^1.0.0 → ^2.0.0 - `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0 - `libdd-trace-utils`: ^8.0.0 → ^9.0.0 ### Commits - chore!: update protobufs to be in sync with datadog-agent (#2180) - feat(stats)!: send telemetry for cardinality limits (#2159) - feat(stats)!: add whole key cardinality limit (#2158) - fix(trace-stats)!: add grpc_method to aggregation key (#2151) - feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061) - feat(data-pipeline)!: export client-computed span stats as OTLP trace metrics (#2067) - refactor(span)!: use VecMap for `meta`, `metrics` and `meta_struct` for v04 spans (#2043) ## libdd-data-pipeline **Next version:** `7.0.0` **Semver bump:** `major` **Tag:** `libdd-data-pipeline-v7.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.2.0 → ^5.1.0 - `libdd-shared-runtime`: ^1.0.0 → ^2.0.0 - `libdd-telemetry`: ^5.0.1 → ^6.0.0 - `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0 - `libdd-trace-stats`: ^5.0.0 → ^6.0.0 - `libdd-trace-utils`: ^8.0.0 → ^9.0.0 ### Commits - feat(trace_exporter): enable telemetry in stats exporter (#2160) - refactor(libdd-telemetry)!: avoid leaking libdd-common types in the public API (#2152) - feat(stats): emit canonical gRPC status name for OTLP rpc.response.status_code (#2183) - feat(data-pipeline): add agentless export (#2081) - feat(stats)!: send telemetry for cardinality limits (#2159) - feat(stats)!: add whole key cardinality limit (#2158) - fix(trace-stats)!: add grpc_method to aggregation key (#2151) - feat(data-pipeline)!: add stdout log trace exporter (#2074) - feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061) - feat(data-pipeline): OTLP HTTP/protobuf trace export (#2115) - feat(otlp)!: Export OTLP spans with attribute-level OTel compatibility (#2091) - feat(data-pipeline)!: export client-computed span stats as OTLP trace metrics (#2067) - chore(stats)!: submit p0 telemetry in stats (#2130) - feat(data-pipeline)!: CSS Trace Filters (#1985) - feat(shared-runtime)!: use weak waker in trigger [APMSP-3371] (#2050) - refactor(span)!: use VecMap for `meta`, `metrics` and `meta_struct` for v04 spans (#2043) - feat(stats)!: add endpoint gating to client-side stats [APMSP-3361] (#2040) ## libdd-dogstatsd-client **Next version:** `4.0.0` **Semver bump:** `major` **Tag:** `libdd-dogstatsd-client-v4.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.1.0 → ^5.1.0 ## libdd-sampling **Next version:** `5.0.0` **Semver bump:** `major` **Tag:** `libdd-sampling-v5.0.0` ###⚠️ major bump forced due to: - `libdd-common`: ^4.2.0 → ^5.1.0 - `libdd-trace-utils`: ^8.0.0 → ^9.0.0 [APMSP-3371]: https://datadoghq.atlassian.net/browse/APMSP-3371?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ --------- Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com> Co-authored-by: iunanua <[email protected]>
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What does this PR do?
Adds criterion microbenchmarks for
VecMap(libdd-trace-utils/src/span/vec_map.rs), the linear-scan ordered map backing each span'smetaandmetrics. The benches isolate the datastructure's core operations across representative map sizes (4, 8, 16, 32, 64), usingBytesStringkeys to match real span usage:insert(construction path),get(hit and miss),get_mut,contains_keyiter(encode path)dedup(runs once per span on decode), with and without duplicate keysas_deduped_map(encode path), both the cheap borrow case and the allocating fallbackA new opt-in
bench-internalsfeature (mirroringlibdd-sampling) gates the bench viarequired-featuresso it is not built by default. The change is additive toCargo.toml.Motivation
VecMapis a swappable datastructure (could be a hashmap/btree) that runs on the tracer hot path, but existing trace-utils benches only measure end-to-end msgpack encode/decode and never isolate it. Since it is linear-scan, the size-vs-operation curve is exactly what should be measured so the backing-structure choice can be revisited with data.Additional Notes
VecMapand thespanmodule are alreadypub, sobench-internalsdoes not gate any source visibility; it is purely an opt-in switch keeping the bench out of the default build, consistent withlibdd-sampling. Data is fully deterministic (no randomness).How to test the change?
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