fix(dogstatsd): Make histogram counts unitless

[atanzu]

Summary

Remove unit field from histogram .counts because those are unitless by nature.

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

How did you test this PR?

Extended the unit test to validate this change.

References

• Fixes: AGTMETRICS-433
• Refers: feat(dogstatsd): add units for timed metrics #1565

[pr-commenter]

Binary Size Analysis (Agent Data Plane)

Target: a0e22b5 (baseline) vs 4745cd6 (comparison) diff
Analysis Type: Stripped binaries (debug symbols excluded)
Baseline Size: 37.61 MiB
Comparison Size: 37.63 MiB
Size Change: +11.62 KiB (+0.03%)
Pass/Fail Threshold: +5%
Result: PASSED ✅

Changes by Module

Module	File Size	Symbols
tower	-6.83 KiB	12
saluki_io::net::util	+4.21 KiB	3
[Unmapped]	-3.61 KiB	1
http_body_util	+2.76 KiB	16
saluki_components::common::otlp	+2.01 KiB	15
tower_layer	+1.89 KiB	1
saluki_components::common::datadog	+1.84 KiB	24
async_compression	+1.73 KiB	5
core	+1.56 KiB	520
[sections]	-1.47 KiB	5
anon.1fe68cbddbd7be3d3efdb1444e7a5632.0.llvm.8454770004358052377	+1.32 KiB	1
anon.d55b423c2f283677f6d773562ab990eb.131.llvm.5604284579821005344	-1.32 KiB	1
anon.83a0cc98dc6ded19c57afb5a6254e931.746.llvm.2527240573028143033	+1.31 KiB	1
anon.d60f603e27f155c11afb6d1f869650cf.5.llvm.32972084449467263	-1.31 KiB	1
anon.c2647432104e31b4fbfcb3327c4ffeed.28.llvm.13672682434017612521	+1.17 KiB	1
anon.612fb6a08a7c80fa0eb437e78cd2cea7.27.llvm.6240974258948202472	-1.17 KiB	1
anon.befc9c1fecd3800de207bb0335981ecb.23.llvm.4205725001344914250	+1.15 KiB	1
anon.be9bca0dc5aba217730cd4a416ef9af1.22.llvm.2621883138078857713	-1.15 KiB	1
saluki_io::compression::Compressor<W>	-1.03 KiB	1
anon.a0a5ca6216b986644a13b3860ee800f1.312.llvm.1489866854082595434	+921 B	1

Detailed Symbol Changes

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  +0.4% +13.9Ki  +0.3% +7.23Ki    [3171 Others]
  [NEW] +4.86Ki  [NEW] +4.66Ki    _<saluki_io::net::util::middleware::retry_circuit_breaker::ResponseFuture<P,F,Request> as core::future::future::Future>::poll::h54feb35fa34fbefe
  [NEW] +2.64Ki  [NEW] +2.54Ki    saluki_components::common::otlp::semantics::Concept::from_str::heab126cd3e207d4a
  [NEW] +2.19Ki  [NEW] +2.02Ki    _<datadog_protos::checks_include::datadog::checks::v1::event::Event as prost::message::Message>::merge_field::h458abdee947281e7
  +296% +1.89Ki  +385% +1.89Ki    _<tower_layer::stack::Stack<Inner,Outer> as tower_layer::Layer<S>>::layer::hb9e23bcd228e099f
  [NEW] +1.78Ki  [NEW]     +47    _<http_body_util::combinators::map_err::MapErr<B,F> as http_body::Body>::size_hint::hbb7ce7c4f4daba75
  [NEW] +1.63Ki  [NEW] +1.39Ki    tokio::sync::broadcast::Shared<T>::notify_rx::h18fb4568ce109d02
  [NEW] +1.38Ki  [NEW] +1.29Ki    h2::proto::streams::counts::Counts::transition::hc3083510479f8559
  [NEW] +1.37Ki  [NEW]    +285    _<http_body_util::combinators::map_frame::MapFrame<B,F> as http_body::Body>::poll_frame::h7d1ef8b49c796c14
  +341% +1.35Ki  +418% +1.35Ki    prost::encoding::merge_loop::h93da6cf4e7852150
  [NEW] +1.32Ki  [NEW]     +88    anon.1fe68cbddbd7be3d3efdb1444e7a5632.0.llvm.8454770004358052377
  [DEL] -1.45Ki  [DEL]     -49    _<http_body_util::combinators::map_err::MapErr<B,F> as http_body::Body>::is_end_stream::h4efc2a12e97b7743
  -0.9% -1.49Ki  -0.9% -1.49Ki    [section .rodata]
  [DEL] -1.61Ki  [DEL] -1.46Ki    _<tower::util::map_request::MapRequestLayer<F> as tower_layer::Layer<S>>::layer::hfc72de87e1a2f5cc
  [DEL] -1.63Ki  [DEL] -1.39Ki    tokio::sync::broadcast::Shared<T>::notify_rx::hd29e16f2862c6775
  [DEL] -1.78Ki  [DEL]     -47    _<http_body_util::combinators::map_err::MapErr<B,F> as http_body::Body>::size_hint::h50b2622ab781d17c
 -82.4% -1.87Ki -85.2% -1.87Ki    prost::encoding::merge_loop::h925221e2058d87a5
  [DEL] -1.90Ki  [DEL] -1.73Ki    _<datadog_protos::checks_include::datadog::checks::v1::metric::Metric as prost::message::Message>::merge_field::h7d941f4b643fc7bb
 -13.5% -2.48Ki -13.6% -2.48Ki    core::ops::function::FnOnce::call_once::h1a7b8751a8007c94
 -47.3% -3.61Ki  [ = ]       0    [Unmapped]
  [DEL] -4.82Ki  [DEL] -4.66Ki    _<tower::limit::concurrency::future::ResponseFuture<F> as core::future::future::Future>::poll::hc82a8bc58d98f9b2
  +0.0% +11.6Ki  +0.0% +7.61Ki    TOTAL

[pr-commenter]

Regression Detector (Agent Data Plane)

Regression Detector Results

Run ID: a09e7793-34db-4130-8589-b7230f4f7b3e

Baseline: a0e22b5
Comparison: 4745cd6
Diff

Optimization Goals: ✅ No significant changes detected

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	otlp_ingest_logs_5mb_throughput	ingress throughput	+0.04	[-0.09, +0.17]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_cpu	% cpu utilization	-0.14	[-4.52, +4.24]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_memory	memory utilization	-0.54	[-0.73, -0.35]	1	(metrics) (profiles) (logs)

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	dsd_uds_1mb_3k_contexts_cpu	% cpu utilization	+3.85	[-53.19, +60.90]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_cpu	% cpu utilization	+2.11	[-27.76, +31.99]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_transform_5mb_cpu	% cpu utilization	+1.12	[-0.82, +3.07]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_throughput	ingress throughput	+1.05	[+0.94, +1.15]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_memory	memory utilization	+0.26	[+0.11, +0.41]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_cpu	% cpu utilization	+0.21	[-1.24, +1.66]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_memory	memory utilization	+0.19	[+0.03, +0.36]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_memory	memory utilization	+0.14	[-0.01, +0.30]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_medium	memory utilization	+0.10	[-0.08, +0.27]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_ultraheavy	memory utilization	+0.09	[-0.03, +0.22]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_throughput	ingress throughput	+0.05	[-0.02, +0.13]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_filtering_5mb_throughput	ingress throughput	+0.05	[-0.03, +0.12]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_throughput	ingress throughput	+0.04	[-0.09, +0.17]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_throughput	ingress throughput	+0.03	[-0.14, +0.19]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_transform_5mb_throughput	ingress throughput	+0.02	[-0.05, +0.09]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_throughput	ingress throughput	+0.00	[-0.06, +0.06]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_throughput	ingress throughput	+0.00	[-0.05, +0.05]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_throughput	ingress throughput	-0.01	[-0.05, +0.02]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_throughput	ingress throughput	-0.03	[-0.18, +0.13]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_transform_5mb_memory	memory utilization	-0.06	[-0.23, +0.10]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_heavy	memory utilization	-0.09	[-0.22, +0.04]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_cpu	% cpu utilization	-0.14	[-4.52, +4.24]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_filtering_5mb_memory	memory utilization	-0.16	[-0.41, +0.08]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_low	memory utilization	-0.19	[-0.36, -0.02]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_memory	memory utilization	-0.21	[-0.36, -0.06]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_memory	memory utilization	-0.25	[-0.41, -0.09]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_idle	memory utilization	-0.27	[-0.31, -0.23]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_memory	memory utilization	-0.34	[-0.48, -0.19]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_cpu	% cpu utilization	-0.49	[-2.53, +1.55]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_memory	memory utilization	-0.54	[-0.73, -0.35]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_memory	memory utilization	-0.74	[-0.95, -0.54]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_cpu	% cpu utilization	-0.84	[-6.62, +4.95]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_ottl_filtering_5mb_cpu	% cpu utilization	-1.06	[-3.40, +1.28]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_cpu	% cpu utilization	-1.10	[-6.55, +4.35]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_cpu	% cpu utilization	-1.85	[-59.34, +55.65]	1	(metrics) (profiles) (logs)

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	observed_value	links
✅	quality_gates_rss_dsd_heavy	memory_usage	10/10	121.37MiB ≤ 140MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_low	memory_usage	10/10	39.95MiB ≤ 50MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_medium	memory_usage	10/10	60.32MiB ≤ 75MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_ultraheavy	memory_usage	10/10	177.83MiB ≤ 200MiB	(metrics) (profiles) (logs)
✅	quality_gates_rss_idle	memory_usage	10/10	26.98MiB ≤ 40MiB	(metrics) (profiles) (logs)

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".