fix(metrics): Make v2 series obey max per-payload series points (1.3.x backport)

[jszwedko]

Summary

Backports #2055 to releases/1.3.x.

Repairs a differential between DogStatsD and ADP: the v2 series request builder now obeys both max_metrics_per_payload and max_series_points_per_payload for /api/v2/series, splitting oversized payloads the same way DogStatsD does. v3 already handled this correctly. The regression was introduced by the metrics-encoder refactor (splitting into endpoint.rs / v2 / v3 modules), which 1.3.x carries.

Clean cherry-pick of 0025407262 (#2055) — 1.3.x shares main's encoder structure.

Validation

• cargo check -p saluki-components passes.
• Unit tests pass, including the new regression test v2_series_builder_enforces_max_series_points_per_payload.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Backport of the v2 series payload-splitting fix to releases/1.3.x, ensuring /api/v2/series request construction enforces both max_metrics_per_payload and max_series_points_per_payload, aligning ADP behavior with DogStatsD (v3 already enforced point limits correctly).

Changes:

• Apply max_series_points_per_payload to the v2 request builder when targeting series endpoints (V1/V2).
• Extend EndpointConfiguration to carry max_series_points_per_payload and thread it through configuration construction.
• Add a regression unit test verifying v2 series payloads never exceed the configured per-payload point limit and that all points are emitted.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
lib/saluki-components/src/encoders/datadog/metrics/v2/mod.rs	Enforces per-payload data-point limits for series endpoints in the v2 request builder.
lib/saluki-components/src/encoders/datadog/metrics/mod.rs	Threads the new endpoint configuration parameter and adds a regression test for v2 point-limit splitting.
lib/saluki-components/src/encoders/datadog/metrics/endpoint.rs	Extends EndpointConfiguration with max_series_points_per_payload and exposes an accessor.

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[pr-commenter]

Binary Size Analysis (Agent Data Plane)

Baseline: f546aa0 · Comparison: cca78dc · diff
Analysis Configuration: stripped binaries · Pass/Fail Threshold: +5%
Sizes: 41.66 MiB (baseline) vs 41.66 MiB (comparison)
Size Change: -5.12 KiB (-0.01%)

✅ Binary size difference within threshold

Changes by Module

Module	File Size	Symbols
anon.4fce6c7d2aa45dd9a6f02a2c0752f076.498.llvm.9573164220153040075	-17.32 KiB	1
anon.c1c414352e857dde7a9d7b1ad53124cc.132.llvm.4296059611656155176	+17.32 KiB	1
anon.7795f5375d38aceee11397747b095f1d.30.llvm.2564832767356818503	+7.24 KiB	1
anon.ad91e51c62512cff203a6c63aaecf20c.398.llvm.18240059250610999947	-7.24 KiB	1
anon.898e98222521ce4d0253cf6d0fc1e7b5.386.llvm.18051895962526366587	+2.29 KiB	1
anon.5b27047855e512a391407cf865a8bccb.8.llvm.4723099464652966178	-2.28 KiB	1
saluki_components::common::datadog	-2.08 KiB	26
tokio	-1.90 KiB	45
anon.4fce6c7d2aa45dd9a6f02a2c0752f076.89.llvm.9174026662507420928	+1.68 KiB	1
anon.71c724bfafdc7ef059b797a72fbace77.13.llvm.8347600808629000313	-1.68 KiB	1
anon.8378b7a0900881ccbbf90fe1ca172908.45.llvm.12360786860623467473	-1.34 KiB	1
anon.84ee839d07d34c4642938df11db7617c.66.llvm.15813203203614711742	-1.34 KiB	1
anon.5565a01ffa835d379ccb42561fbc2231.58.llvm.14277099931082214193	+1.34 KiB	1
anon.9e7fe21941eb14193087d4323bb508b7.149.llvm.18246841136514536931	+1.34 KiB	1
anon.9f57deab38cb447f7dd82e5766cd87af.24.llvm.16874604699339231193	-1.33 KiB	1
anon.5b93ae75a70061f493f939c9825259bb.56.llvm.7062792288990175982	+1.32 KiB	1
anon.4ad83413d91ec1b5e3631d1dde603515.3.llvm.14890587780386234679	-1.23 KiB	1
anon.54d99dc5dd0affd1e8de0751295dc995.1100.llvm.7520400692622734692	+1.23 KiB	1
core	-1.20 KiB	297
anon.71cec01b0fb3e883aa3d98671f1fd27a.314.llvm.9747834397690803415	+1.15 KiB	1

Detailed Symbol Changes

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  [NEW] +17.3Ki  [NEW]     +81    anon.c1c414352e857dde7a9d7b1ad53124cc.132.llvm.4296059611656155176
  [NEW] +7.24Ki  [NEW]     +79    anon.7795f5375d38aceee11397747b095f1d.30.llvm.2564832767356818503
  [NEW] +2.36Ki  [NEW] +2.21Ki    saluki_components::encoders::datadog::metrics::v2::create_v2_request_builder::_{{closure}}::h2e1993ad4d90ef2d
  [NEW] +2.29Ki  [NEW]     +76    anon.898e98222521ce4d0253cf6d0fc1e7b5.386.llvm.18051895962526366587
  [NEW] +2.10Ki  [NEW]     +61    core::ptr::drop_in_place<std::sync::poison::PoisonError<std::sync::poison::rwlock::RwLockReadGuard<quick_cache::shard::CacheShard<stringtheory::MetaString,core::option::Option<saluki_components::transforms::dogstatsd_mapper::CachedMapResult>,saluki_common::cache::weight::WrappedWeighter<saluki_common::cache::weight::ItemCountWeighter>,foldhash::quality::RandomState,saluki_common::cache::expiry::ExpiryCapableLifecycle<stringtheory::MetaString>,alloc::sync::Arc<quick_cache::sync_placeholder::Placeholder<core::option::Option<saluki_components::transforms::dogstatsd_mapper::CachedMapResult>>>>>>>::hf6397604845b9bd1
  [NEW] +1.68Ki  [NEW]     +95    anon.4fce6c7d2aa45dd9a6f02a2c0752f076.89.llvm.9174026662507420928
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  [NEW] +1.31Ki  [NEW] +1.03Ki    quick_cache::shard::CacheShard<Key,Val,We,B,L,Plh>::search::hb55e8b815e013c3e
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  [DEL] -1.34Ki  [DEL]     -22    anon.8378b7a0900881ccbbf90fe1ca172908.45.llvm.12360786860623467473
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  [DEL] -1.68Ki  [DEL]     -95    anon.71c724bfafdc7ef059b797a72fbace77.13.llvm.8347600808629000313
  [DEL] -2.10Ki  [DEL]     -61    core::ptr::drop_in_place<std::sync::poison::PoisonError<std::sync::poison::rwlock::RwLockReadGuard<quick_cache::shard::CacheShard<alloc::string::String,saluki_components::sources::otlp::metrics::cache::Extrema,saluki_common::cache::weight::WrappedWeighter<saluki_common::cache::weight::ItemCountWeighter>,foldhash::quality::RandomState,saluki_common::cache::expiry::ExpiryCapableLifecycle<alloc::string::String>,alloc::sync::Arc<quick_cache::sync_placeholder::Placeholder<saluki_components::sources::otlp::metrics::cache::Extrema>>>>>>::h26e4c7e16f0481e3
  [DEL] -2.28Ki  [DEL]     -76    anon.5b27047855e512a391407cf865a8bccb.8.llvm.4723099464652966178
  [DEL] -2.33Ki  [DEL] -2.19Ki    saluki_components::encoders::datadog::metrics::v2::create_v2_request_builder::_{{closure}}::h60f188077acb0e58
  -0.2% -5.13Ki  -0.1% -3.40Ki    [4175 Others]
  [DEL] -7.24Ki  [DEL]     -79    anon.ad91e51c62512cff203a6c63aaecf20c.398.llvm.18240059250610999947
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  -0.0% -5.12Ki  -0.0% -3.38Ki    TOTAL

[pr-commenter]

Regression Detector (Agent Data Plane)

Run ID: 23b8380a-1c7b-4e09-a75a-bc3e23e889e4
Baseline: f546aa02 · Comparison: cca78dc6 · diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment (5)

Experiments configured erratic: true are tagged (ignored) and skipped when determining which experiments regressed or improved. Experiments which are detected as erratic at runtime are tagged (erratic) to flag that the run's sample dispersion was high, but their regression / improvement signal still counts.

experiment	goal	Δ mean %	links
quality_gates_rss_dsd_low	memory	⚪ +0.25	metrics profiles logs
quality_gates_rss_idle	memory	⚪ +0.17	metrics profiles logs
quality_gates_rss_dsd_ultraheavy	memory	⚪ -0.03	metrics profiles logs
quality_gates_rss_dsd_heavy	memory	⚪ -0.17	metrics profiles logs
quality_gates_rss_dsd_medium	memory	⚪ -0.27	metrics profiles logs

Bounds Checks: ✅ Passed (5)

experiment	check	replicates	observed	links
quality_gates_rss_dsd_heavy	memory_usage	10/10	✅ 135 MiB ≤ 140 MiB	metrics profiles logs
quality_gates_rss_dsd_low	memory_usage	10/10	✅ 42.9 MiB ≤ 50 MiB	metrics profiles logs
quality_gates_rss_dsd_medium	memory_usage	10/10	✅ 64.8 MiB ≤ 75 MiB	metrics profiles logs
quality_gates_rss_dsd_ultraheavy	memory_usage	10/10	✅ 192 MiB ≤ 200 MiB	metrics profiles logs
quality_gates_rss_idle	memory_usage	10/10	✅ 29 MiB ≤ 40 MiB	metrics profiles logs

Explanation

A change is flagged as a regression when |Δ mean %| > 5.00% in the regressing direction for its optimization goal AND SMP marks the experiment as a regression (is_regression: true). Improvements use the matching criteria for the improving direction. Experiments configured erratic: true (tagged (ignored)) are skipped outright; experiments detected as erratic at runtime (tagged (erratic)) still count, since that flag describes sample dispersion rather than directional certainty. The Δ mean % cell is colored accordingly: 🟢 = improvement, 🔴 = regression, ⚪ = neutral. Reduction in CPU or memory is an improvement; reduction in ingress throughput is a regression.