feat(agent-data-plane): Add OTTL filter processor component skeleton

[RiantZ]

Summary

ADP Pipeline component that drops spans (not yet supported: span events, metrics, datapoints, and logs) when any OTTL (OpenTelemetry Transformation Language) conditions evaluate to true.

Example of configuration:

ottl_config:
  error_mode: ignore
  traces:
    span:
      - 'attributes["container.name"] == "app_container_1"'
      - 'resource.attributes["host.name"] == "localhost"'

Behavior is aligned with the OSS filterprocessor

Current support:

• Filtering by multiple OTTL predicates is supported.
• The component’s configuration is global for all component instances (a temporary solution for the POC).
• Currently, filtering applies only to span attributes and resource attributes.

Change Type

• New feature

How did you test this PR?

Manual tests

[OTAGENT-834](https://datadoghq.atlassian.net/browse/OTAGENT-834)

[pr-commenter]

Regression Detector (Agent Data Plane)

Regression Detector Results

Run ID: 1ef6fda0-145a-429f-a668-feecf1f78727

Baseline: 5bf6eb8
Comparison: 375d6c3
Diff

❌ Experiments with retried target crashes

This is a critical error. One or more replicates failed with a non-zero exit code. These replicates may have been retried. See Replicate Execution Details for more information.

• otlp_ingest_traces_5mb_throughput
• otlp_ingest_metrics_5mb_cpu
• otlp_ingest_logs_5mb_memory
• quality_gates_rss_dsd_heavy

Optimization Goals: ✅ Improvement(s) detected

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
✅	otlp_ingest_traces_5mb_memory	memory utilization	-6.30	[-6.57, -6.03]	1	(metrics) (profiles) (logs)

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_memory	memory utilization	+5.58	[+4.91, +6.24]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_cpu	% cpu utilization	+4.41	[-0.82, +9.65]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_throughput	ingress throughput	-0.01	[-0.14, +0.12]	1	(metrics) (profiles) (logs)

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
❌	otlp_ingest_logs_5mb_memory	memory utilization	+5.58	[+4.91, +6.24]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_cpu	% cpu utilization	+4.41	[-0.82, +9.65]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_memory	memory utilization	+3.34	[+3.15, +3.53]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_idle	memory utilization	+1.14	[+1.10, +1.18]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_memory	memory utilization	+0.78	[+0.58, +0.98]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_memory	memory utilization	+0.76	[+0.57, +0.94]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_low	memory utilization	+0.75	[+0.59, +0.91]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_memory	memory utilization	+0.70	[+0.51, +0.90]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_memory	memory utilization	+0.67	[+0.48, +0.86]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_cpu	% cpu utilization	+0.51	[-1.57, +2.59]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_memory	memory utilization	+0.42	[+0.23, +0.61]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_ultraheavy	memory utilization	+0.24	[+0.11, +0.37]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_throughput	ingress throughput	+0.22	[+0.08, +0.35]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_heavy	memory utilization	+0.17	[+0.04, +0.29]	1	(metrics) (profiles) (logs)
➖	quality_gates_rss_dsd_medium	memory utilization	+0.08	[-0.11, +0.28]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_throughput	ingress throughput	+0.04	[-0.08, +0.16]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_throughput	ingress throughput	+0.00	[-0.05, +0.06]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_throughput	ingress throughput	+0.00	[-0.06, +0.06]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_traces_5mb_throughput	ingress throughput	-0.00	[-0.02, +0.02]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_throughput	ingress throughput	-0.00	[-0.05, +0.05]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_throughput	ingress throughput	-0.01	[-0.17, +0.15]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_logs_5mb_throughput	ingress throughput	-0.01	[-0.14, +0.12]	1	(metrics) (profiles) (logs)
➖	dsd_uds_500mb_3k_contexts_cpu	% cpu utilization	-0.06	[-1.34, +1.21]	1	(metrics) (profiles) (logs)
➖	dsd_uds_10mb_3k_contexts_cpu	% cpu utilization	-0.79	[-28.52, +26.94]	1	(metrics) (profiles) (logs)
➖	dsd_uds_100mb_3k_contexts_cpu	% cpu utilization	-1.06	[-6.75, +4.64]	1	(metrics) (profiles) (logs)
➖	otlp_ingest_metrics_5mb_cpu	% cpu utilization	-1.21	[-7.21, +4.78]	1	(metrics) (profiles) (logs)
➖	dsd_uds_1mb_3k_contexts_cpu	% cpu utilization	-3.31	[-54.97, +48.35]	1	(metrics) (profiles) (logs)
✅	otlp_ingest_traces_5mb_memory	memory utilization	-6.30	[-6.57, -6.03]	1	(metrics) (profiles) (logs)
➖	dsd_uds_512kb_3k_contexts_cpu	% cpu utilization	-15.35	[-67.59, +36.89]	1	(metrics) (profiles) (logs)

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	links
✅	quality_gates_rss_dsd_heavy	memory_usage	10/10	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_low	memory_usage	10/10	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_medium	memory_usage	10/10	(metrics) (profiles) (logs)
✅	quality_gates_rss_dsd_ultraheavy	memory_usage	10/10	(metrics) (profiles) (logs)
✅	quality_gates_rss_idle	memory_usage	10/10	(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".

Replicate Execution Details

We run multiple replicates for each experiment/variant. However, we allow replicates to be automatically retried if there are any failures, up to 8 times, at which point the replicate is marked dead and we are unable to run analysis for the entire experiment. We call each of these attempts at running replicates a replicate execution. This section lists all replicate executions that failed due to the target crashing or being oom killed.

Note: In the below tables we bucket failures by experiment, variant, and failure type. For each of these buckets we list out the replicate indexes that failed with an annotation signifying how many times said replicate failed with the given failure mode. In the below example the baseline variant of the experiment named experiment_with_failures had two replicates that failed by oom kills. Replicate 0, which failed 8 executions, and replicate 1 which failed 6 executions, all with the same failure mode.

Experiment	Variant	Replicates	Failure	Logs	Debug Dashboard
experiment_with_failures	baseline	0 (x8) 1 (x6)	Oom killed		Debug Dashboard

The debug dashboard links will take you to a debugging dashboard specifically designed to investigate replicate execution failures.

❌ Retried Normal Replicate Execution Failures (non-profiling)

Experiment	Variant	Replicates	Failure	Debug Dashboard
otlp_ingest_logs_5mb_memory	comparison	7	Failed to shutdown when requested	Debug Dashboard
otlp_ingest_metrics_5mb_cpu	baseline	1	Failed to shutdown when requested	Debug Dashboard
otlp_ingest_traces_5mb_throughput	baseline	0	Failed to shutdown when requested	Debug Dashboard
quality_gates_rss_dsd_heavy	comparison	5	Failed to shutdown when requested	Debug Dashboard

[tobz]

Overall, this looks good to me just to give us something to start experimenting with.

[tobz]

We could definitely modify this function to return Result<bool, GenericError> to encode all the possible outcomes, and we could probably write a version of Trace::retain_spans that allowed for a fallible predicate which short circuited... but this could get complex very quickly, though, because of the need to make everything fallible.

Looking at the documentation for filterprocessor, I suspect we might end up wanting (or needing) a higher-level data structure to hold the "result" of each parser execution, in order to allow us to handle the more advanced "context inferrer" logic, but also us to generically represent the outcomes -- keep this span/spanevent/metric/etc, or don't keep it -- without needing specialized versions of retain_* for each one that allows for short circuiting, etc.

[pr-commenter]

Binary Size Analysis (Agent Data Plane)

Target: 5bf6eb8 (baseline) vs 6bf69ea (comparison) diff
Analysis Type: Stripped binaries (debug symbols excluded)
Baseline Size: 26.90 MiB
Comparison Size: 27.39 MiB
Size Change: +497.91 KiB (+1.81%)
Pass/Fail Threshold: +5%
Result: PASSED ✅

Changes by Module

Module	File Size	Symbols
core	+268.47 KiB	3377
chumsky	+97.08 KiB	42
agent_data_plane::components::ottl_filter_processor	+36.23 KiB	17
[sections]	+17.88 KiB	8
ottl::parser::eval	+13.21 KiB	8
ottl::lexer::Token	+12.64 KiB	27
alloc	+11.13 KiB	369
ottl::parser::arena	+8.58 KiB	5
figment	+7.83 KiB	61
ottl::parser::grammar	+6.49 KiB	9
hashbrown	+5.87 KiB	73
ottl::Value	+5.53 KiB	4
saluki_components::transforms::chained	+3.58 KiB	4
serde_core	+3.56 KiB	84
ottl::parser::ops	+2.67 KiB	1
[Unmapped]	-1.59 KiB	1
agent_data_plane::cli::run	-1.03 KiB	70
ottl::lexer::LexerError	+815 B	1
std	-746 B	123
saluki_env::helpers::remote_agent	-456 B	4

Detailed Symbol Changes

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  [NEW] +1.79Mi  [NEW] +1.79Mi    std::thread::local::LocalKey<T>::with::he359acebcd355a42
  +9.6%  +494Ki  +7.1%  +294Ki    [7778 Others]
  [NEW]  +113Ki  [NEW]  +113Ki    agent_data_plane::cli::run::create_topology::_{{closure}}::hc645b34a68b8f71e
  [NEW] +84.5Ki  [NEW] +84.4Ki    agent_data_plane::internal::control_plane::spawn_control_plane::_{{closure}}::hd6ee71eb8e3b5d42
  [NEW] +57.9Ki  [NEW] +57.7Ki    agent_data_plane::cli::run::handle_run_command::_{{closure}}::h3f44cf5951d01919
  [NEW] +48.9Ki  [NEW] +48.8Ki    saluki_app::bootstrap::AppBootstrapper::bootstrap::_{{closure}}::h08a8f41b52f72e34
  [NEW] +44.1Ki  [NEW] +44.0Ki    saluki_env::workload::providers::remote_agent::RemoteAgentWorkloadProvider::from_configuration::_{{closure}}::hc491aca4a43dc516
  [NEW] +38.1Ki  [NEW] +38.0Ki    agent_data_plane::run_inner::_{{closure}}::h877e1870ab1bc351
  [NEW] +36.1Ki  [NEW]    +192    core::ptr::drop_in_place<chumsky::combinator::Foldl<ottl::parser::grammar::build_parser::{{closure}}::{{closure}},chumsky::combinator::Foldl<ottl::parser::grammar::build_parser::{{closure}}::{{closure}},chumsky::combinator::Map<chumsky::combinator::Then<chumsky::combinator::OrNot<chumsky::primitive::Just<&ottl::lexer::Token,&[ottl::lexer::Token],chumsky::extra::Full<chumsky::error::Rich<ottl::lexer::Token>,$LP$$RP$,$LP$$RP$>>>,chumsky::primitive::Choice<$LP$chumsky::combinator::DelimitedBy<chumsky::recursive::Recursive<dyn chumsky::Parser<&[ottl::lexer::Token],ottl::parser::ast::BoolExpr,chumsky::extra::Full<chumsky::error::Rich<ottl::lexer::Token>,$LP$$RP$,$LP$$RP$>>>,chumsky::primitive::Just<&ottl::lexer::Token,&[ottl::lexer::Token],chumsky::extra::Full<chumsky::error::Rich<ottl::lexer::Token>$
  [NEW] +35.9Ki  [NEW] +35.7Ki    saluki_env::helpers::remote_agent::client::RemoteAgentClient::from_configuration::_{{closure}}::_{{closure}}::_{{closure}}::h1e5186b3677591e6
  [NEW] +35.3Ki  [NEW] +35.1Ki    _<saluki_config::secrets::resolver::external::ExternalProcessResolver as saluki_config::secrets::resolver::Resolver>::resolve::_{{closure}}::h377cb0d1ae9ccf4f
  [DEL] -32.8Ki  [DEL] -32.6Ki    agent_data_plane::cli::dogstatsd::handle_dogstatsd_stats::_{{closure}}::hb8cafd703c5ed08d
  [DEL] -35.3Ki  [DEL] -35.1Ki    _<saluki_config::secrets::resolver::external::ExternalProcessResolver as saluki_config::secrets::resolver::Resolver>::resolve::_{{closure}}::h868cfb2b64303c87
  [DEL] -35.9Ki  [DEL] -35.7Ki    saluki_env::helpers::remote_agent::client::RemoteAgentClient::from_configuration::_{{closure}}::_{{closure}}::_{{closure}}::h451602f339bf9b6d
  [DEL] -38.1Ki  [DEL] -38.0Ki    agent_data_plane::run_inner::_{{closure}}::h4bd94e0532d6b630
  [DEL] -44.1Ki  [DEL] -44.0Ki    saluki_env::workload::providers::remote_agent::RemoteAgentWorkloadProvider::from_configuration::_{{closure}}::hb64db5e615713673
  [DEL] -48.8Ki  [DEL] -48.7Ki    saluki_app::bootstrap::AppBootstrapper::bootstrap::_{{closure}}::hca5d8d0e9367596a
  [DEL] -57.7Ki  [DEL] -57.6Ki    agent_data_plane::cli::run::handle_run_command::_{{closure}}::he1c11d97bbc07545
  [DEL] -84.5Ki  [DEL] -84.4Ki    agent_data_plane::internal::control_plane::spawn_control_plane::_{{closure}}::h34d667a7fe151224
  [DEL]  -114Ki  [DEL]  -114Ki    agent_data_plane::cli::run::create_topology::_{{closure}}::h242100d6d38705c3
  [DEL] -1.79Mi  [DEL] -1.79Mi    std::thread::local::LocalKey<T>::with::h69bf559e2b2ff5e4
  +1.8%  +497Ki  +1.1%  +261Ki    TOTAL