move apm language detection config under apm_config.instrumentation

[adel121]

What does this PR do?

Move APM language detection configurations under apm_config in config package.

Motivation

Achieve separation between:

• language detection performed b process-agent (detecting languages on the level of processes)
• language detection performed by core agent and cluster agent (collecting process-level languages and aggregating them by deployment-level).

This change has no impact on the functional aspects of the feature.

Additional Notes

• This should be merged in 7.52.0 because it is related to a new feature and changing feature configuration in the future in this manner will break existing deployments with old configurations.

Possible Drawbacks / Trade-offs

• Should not change behaviour at all, it is only renaming environment variables and changing bindings in config.

Describe how to test/QA your changes

Same QA as this PR.

[pr-commenter]

Bloop Bleep... Dogbot Here

Regression Detector Results

Run ID: da519242-f00c-464f-8444-ba51ac83e295
Baseline: e0749a8
Comparison: e756063
Total CPUs: 7

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

Experiments with missing or malformed data

• basic_py_check

Usually, this warning means that there is no usable optimization goal data for that experiment, which could be a result of misconfiguration.

No significant changes in experiment optimization goals

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

There were no significant changes in experiment optimization goals at this confidence level and effect size tolerance.

Experiments ignored for regressions

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

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	file_to_blackhole	% cpu utilization	+0.24	[-6.31, +6.79]

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	otel_to_otel_logs	ingress throughput	+0.94	[+0.30, +1.57]
➖	file_tree	memory utilization	+0.76	[+0.63, +0.88]
➖	process_agent_real_time_mode	memory utilization	+0.35	[+0.30, +0.39]
➖	tcp_syslog_to_blackhole	ingress throughput	+0.28	[+0.22, +0.35]
➖	file_to_blackhole	% cpu utilization	+0.24	[-6.31, +6.79]
➖	process_agent_standard_check_with_stats	memory utilization	+0.18	[+0.13, +0.22]
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.00, +0.00]
➖	tcp_dd_logs_filter_exclude	ingress throughput	+0.00	[-0.00, +0.00]
➖	trace_agent_json	ingress throughput	-0.03	[-0.07, +0.00]
➖	trace_agent_msgpack	ingress throughput	-0.05	[-0.06, -0.03]
➖	process_agent_standard_check	memory utilization	-0.23	[-0.27, -0.20]
➖	idle	memory utilization	-0.34	[-0.38, -0.30]
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-2.08	[-3.48, -0.68]

Explanation

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".

[clamoriniere]

I though apm_config was limited to the trace-agent configuration.
if we use it in the cluster-agent it means that we need to load the trace-agent config

[clamoriniere]

I think this parameters are not specific to APM. since we can imagine we have other usage of the langage information stored on top of the Deployment

I would suggestion to have a dedicated config section for it.

language_detection.resources_configuration.client_period

[adel121]

close in favour of this PR