Make # of log pipelines configurable and default to GOMAXPROCS

[gh123man]

What does this PR do?

Makes the # of logs pipelines configurable (previously hard coded to 4) and set the default to GOMAXPROCS with a soft maximum of 4.

Motivation

Logs pipelines are inherently limited by a single CPU core due to compression overhead. The previous hardcoded setting of 4 was overfit for small hosts, and possibly underfit for large hosts (with more than 4 cores available).

With this change we set the number of pipelines to GOMAXPROCS but also allow it to be customized manually by logs_config.pipelines. Limiting the setting to 4 ensures hosts with a lot of CPUs don't over provision too many logs pipelines but leaves room to adjust if needed.

Describe how to test/QA your changes

QA done by validating the logs agent still works (SMP results in PR).

• This should have no out of the box behavior change. Agent will just better utilize available resources.

Possible Drawbacks / Trade-offs

Additional Notes

[agent-platform-auto-pr]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv create-vm --pipeline-id=49608501 --os-family=ubuntu

Note: This applies to commit d99f56a

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 376df6fd-4796-4293-90ad-9f540156dc3b

Baseline: 52173be
Comparison: d99f56a
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	basic_py_check	% cpu utilization	+3.97	[+0.07, +7.86]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	+0.69	[+0.57, +0.80]	1	Logs bounds checks dashboard
➖	file_tree	memory utilization	+0.51	[+0.36, +0.65]	1	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+0.49	[-0.25, +1.22]	1	Logs
➖	otel_to_otel_logs	ingress throughput	+0.31	[-0.35, +0.96]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	+0.21	[-0.55, +0.97]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.05	[-0.73, +0.83]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	+0.04	[-0.74, +0.83]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.08, +0.09]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	-0.02	[-0.70, +0.66]	1	Logs
➖	quality_gate_idle	memory utilization	-0.15	[-0.20, -0.11]	1	Logs bounds checks dashboard
➖	file_to_blackhole_300ms_latency	egress throughput	-0.25	[-0.88, +0.38]	1	Logs
➖	file_to_blackhole_1000ms_latency_linear_load	egress throughput	-0.46	[-0.91, +0.00]	1	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	-0.54	[-0.61, -0.48]	1	Logs
➖	pycheck_lots_of_tags	% cpu utilization	-1.12	[-4.56, +2.32]	1	Logs

Bounds Checks: ❌ Failed

perf	experiment	bounds_check_name	replicates_passed	links
❌	file_to_blackhole_1000ms_latency	lost_bytes	0/10
❌	file_to_blackhole_500ms_latency	lost_bytes	8/10
❌	file_to_blackhole_100ms_latency	lost_bytes	9/10
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency_linear_load	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_300ms_latency	lost_bytes	10/10
✅	file_to_blackhole_300ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard

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".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.

[gh123man]

Other teams that review this for the non-logs components:

• Do you want to use the same # of pipelines as the logs agent all the time? or would you prefer a different default setting? (Currently using the same as the logs pipeline)

[sgnn7]

@gh123man One small nit but not a blocker

[remeh]

This PR will double the amount of (possible idle) connections to the intake, let's make sure it's fine, but otherwise, LGTM!

[jackgopack4]

just to be clear, if this value is not set by the user, the default is still applied? I want to make sure because we use this dependency in the upstream collector and there wouldn't be a way for the user to specify it currently

[gh123man]

If the collector uses the same default configurations as the agent uses - yes it will use the default value here. The default was just moved to the config instead of being hard coded so a user could configure it if they wanted.

To be safe (if you want) - I could return this line back to the original default (4) as I did for the security and compliance agent.

[jackgopack4]

is this still happening?

[gh123man]

@jackgopack4 Yep! Was blocked by the merge freeze - thanks for the signoff!

[gh123man]

/merge

[dd-devflow]

Devflow running: /merge

View all feedbacks in Devflow UI.

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2024-12-10 10:09:48 UTC ℹ️ MergeQueue: pull request added to the queue

The median merge time in main is 24m.