[AGNTLOG-618] Default file_scan_period to 1s

[ddrthall]

What does this PR do?

• Changes the default value of logs_config.file_scan_period from 10 seconds to 1 second.
• Updates pkg/config/schema/core_schema.yaml to match the new default.
• Adds a release note describing the change and how to opt out (slower scan) on hosts that need it.

Motivation

The file log launcher uses this setting to schedule periodic filesystem scans for file-based log sources (new files, wildcards, rotation, and open-files selection). A 1 second default shortens the worst-case delay before the Agent discovers and starts tailing a new or rotated file. Deployments on slow or network-backed filesystems that need to limit metadata load can set logs_config.file_scan_period to a higher value in configuration.

Describe how you validated your changes

• inv test --targets=./pkg/config/setup (all tests passed).

Additional Notes

• This only affects the file log launcher’s scan cadence, not the idle read interval for an already open file.
• Users with an explicit logs_config.file_scan_period in datadog.yaml (or equivalent) are unchanged.

[datadog-official]

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 50.16% (-0.01%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: ce4c9f7 | Docs | Datadog PR Page | Give us feedback!}

[dd-octo-sts]

Files inventory check summary

File checks results against ancestor 443f58ee:

Results for datadog-agent_7.80.0~devel.git.220.ce4c9f7.pipeline.109675094-1_amd64.deb:

No change detected

[dd-octo-sts]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor 443f58e
📊 Static Quality Gates Dashboard
🔗 SQG Job

31 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_deb_amd64	740.333 MiB
✅	agent_deb_amd64_fips	698.767 MiB
✅	agent_heroku_amd64	310.468 MiB
✅	agent_msi	604.095 MiB
✅	agent_rpm_amd64	740.317 MiB
✅	agent_rpm_amd64_fips	698.751 MiB
✅	agent_rpm_arm64	718.427 MiB
✅	agent_rpm_arm64_fips	679.886 MiB
✅	agent_suse_amd64	740.317 MiB
✅	agent_suse_amd64_fips	698.751 MiB
✅	agent_suse_arm64	718.427 MiB
✅	agent_suse_arm64_fips	679.886 MiB
✅	docker_agent_amd64	800.791 MiB
✅	docker_agent_arm64	803.711 MiB
✅	docker_agent_jmx_amd64	991.711 MiB
✅	docker_agent_jmx_arm64	983.409 MiB
✅	docker_cluster_agent_amd64	206.257 MiB
✅	docker_cluster_agent_arm64	220.383 MiB
✅	docker_cws_instrumentation_amd64	7.142 MiB
✅	docker_cws_instrumentation_arm64	6.689 MiB
✅	docker_dogstatsd_amd64	39.343 MiB
✅	docker_dogstatsd_arm64	37.565 MiB
✅	dogstatsd_deb_amd64	30.001 MiB
✅	dogstatsd_deb_arm64	28.142 MiB
✅	dogstatsd_rpm_amd64	30.001 MiB
✅	dogstatsd_suse_amd64	30.001 MiB
✅	iot_agent_deb_amd64	44.372 MiB
✅	iot_agent_deb_arm64	41.361 MiB
✅	iot_agent_deb_armhf	42.097 MiB
✅	iot_agent_rpm_amd64	44.373 MiB
✅	iot_agent_suse_amd64	44.373 MiB

On-wire sizes (compressed)

	Quality gate	Change	Size (prev → curr → max)
✅	agent_deb_amd64	-6.81 KiB (0.00% reduction)	175.139 → 175.132 → 179.160
✅	agent_deb_amd64_fips	-17.56 KiB (0.01% reduction)	166.972 → 166.955 → 174.440
✅	agent_heroku_amd64	-5.16 KiB (0.01% reduction)	75.094 → 75.089 → 80.310
✅	agent_msi	-20.0 KiB (0.01% reduction)	139.289 → 139.270 → 147.550
✅	agent_rpm_amd64	+53.24 KiB (0.03% increase)	177.116 → 177.168 → 182.080
✅	agent_rpm_amd64_fips	+18.13 KiB (0.01% increase)	168.319 → 168.336 → 174.140
✅	agent_rpm_arm64	-6.1 KiB (0.00% reduction)	159.483 → 159.477 → 163.610
✅	agent_rpm_arm64_fips	-11.36 KiB (0.01% reduction)	151.646 → 151.635 → 156.850
✅	agent_suse_amd64	+53.24 KiB (0.03% increase)	177.116 → 177.168 → 182.080
✅	agent_suse_amd64_fips	+18.13 KiB (0.01% increase)	168.319 → 168.336 → 174.140
✅	agent_suse_arm64	-6.1 KiB (0.00% reduction)	159.483 → 159.477 → 163.610
✅	agent_suse_arm64_fips	-11.36 KiB (0.01% reduction)	151.646 → 151.635 → 156.850
✅	docker_agent_amd64	neutral	267.434 MiB → 272.990
✅	docker_agent_arm64	neutral	254.474 MiB → 261.470
✅	docker_agent_jmx_amd64	neutral	336.088 MiB → 341.610
✅	docker_agent_jmx_arm64	neutral	319.120 MiB → 326.050
✅	docker_cluster_agent_amd64	neutral	72.288 MiB → 73.460
✅	docker_cluster_agent_arm64	neutral	67.757 MiB → 68.680
✅	docker_cws_instrumentation_amd64	neutral	2.999 MiB → 3.330
✅	docker_cws_instrumentation_arm64	neutral	2.729 MiB → 3.090
✅	docker_dogstatsd_amd64	neutral	15.228 MiB → 15.870
✅	docker_dogstatsd_arm64	neutral	14.544 MiB → 14.890
✅	dogstatsd_deb_amd64	-4.02 KiB (0.05% reduction)	7.938 → 7.934 → 8.830
✅	dogstatsd_deb_arm64	+2.47 KiB (0.04% increase)	6.817 → 6.819 → 7.750
✅	dogstatsd_rpm_amd64	neutral	7.948 MiB → 8.840
✅	dogstatsd_suse_amd64	neutral	7.948 MiB → 8.840
✅	iot_agent_deb_amd64	neutral	11.678 MiB → 13.210
✅	iot_agent_deb_arm64	neutral	9.982 MiB → 11.620
✅	iot_agent_deb_armhf	neutral	10.186 MiB → 11.780
✅	iot_agent_rpm_amd64	-2.04 KiB (0.02% reduction)	11.700 → 11.698 → 13.230
✅	iot_agent_suse_amd64	-2.04 KiB (0.02% reduction)	11.700 → 11.698 → 13.230

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 60a41069-f9d8-4607-9f9a-60f4769b45a2

Baseline: 2496635
Comparison: ca131ce
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.

• docker_containers_cpu
• docker_containers_memory

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
➖	docker_containers_cpu	% cpu utilization	+3.16	[+0.12, +6.20]	1	Logs

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	docker_containers_cpu	% cpu utilization	+3.16	[+0.12, +6.20]	1	Logs
➖	quality_gate_metrics_logs	memory utilization	+1.05	[+0.79, +1.30]	1	Logs bounds checks dashboard
➖	tcp_syslog_to_blackhole	ingress throughput	+0.62	[+0.48, +0.76]	1	Logs
➖	ddot_metrics	memory utilization	+0.24	[+0.04, +0.45]	1	Logs
➖	otlp_ingest_metrics	memory utilization	+0.23	[+0.07, +0.38]	1	Logs
➖	quality_gate_idle	memory utilization	+0.20	[+0.15, +0.25]	1	Logs bounds checks dashboard
➖	ddot_metrics_sum_delta	memory utilization	+0.16	[-0.03, +0.35]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	+0.06	[+0.03, +0.10]	1	Logs bounds checks dashboard
➖	docker_containers_memory	memory utilization	+0.06	[-0.06, +0.18]	1	Logs
➖	file_tree	memory utilization	+0.05	[+0.00, +0.09]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.03	[-0.44, +0.50]	1	Logs
➖	ddot_metrics_sum_cumulative	memory utilization	+0.00	[-0.16, +0.16]	1	Logs
➖	uds_dogstatsd_to_api_v3	ingress throughput	-0.00	[-0.20, +0.20]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.00	[-0.21, +0.20]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.01	[-0.11, +0.09]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.01	[-0.39, +0.37]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	-0.02	[-0.13, +0.09]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.04	[-0.47, +0.40]	1	Logs
➖	otlp_ingest_logs	memory utilization	-0.15	[-0.24, -0.06]	1	Logs
➖	ddot_metrics_sum_cumulativetodelta_exporter	memory utilization	-0.17	[-0.41, +0.07]	1	Logs
➖	uds_dogstatsd_20mb_12k_contexts_20_senders	memory utilization	-0.25	[-0.31, -0.20]	1	Logs
➖	quality_gate_logs	% cpu utilization	-0.66	[-1.98, +0.66]	1	Logs bounds checks dashboard
➖	ddot_logs	memory utilization	-0.77	[-0.84, -0.69]	1	Logs

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	observed_value	links
✅	docker_containers_cpu	simple_check_run	10/10	721 ≥ 26
✅	docker_containers_memory	memory_usage	10/10	244.65MiB ≤ 370MiB
✅	docker_containers_memory	simple_check_run	10/10	713 ≥ 26
✅	file_to_blackhole_0ms_latency	memory_usage	10/10	0.16GiB ≤ 1.20GiB
✅	file_to_blackhole_0ms_latency	missed_bytes	10/10	0B = 0B
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10	0.21GiB ≤ 1.20GiB
✅	file_to_blackhole_1000ms_latency	missed_bytes	10/10	0B = 0B
✅	file_to_blackhole_100ms_latency	memory_usage	10/10	0.17GiB ≤ 1.20GiB
✅	file_to_blackhole_100ms_latency	missed_bytes	10/10	0B = 0B
✅	file_to_blackhole_500ms_latency	memory_usage	10/10	0.18GiB ≤ 1.20GiB
✅	file_to_blackhole_500ms_latency	missed_bytes	10/10	0B = 0B
✅	quality_gate_idle	intake_connections	10/10	3 ≤ 4	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	139.59MiB ≤ 147MiB	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	3 ≤ 4	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	465.28MiB ≤ 495MiB	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	3 ≤ 6	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	172.91MiB ≤ 195MiB	bounds checks dashboard
✅	quality_gate_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	342.99 ≤ 2000	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	3 ≤ 6	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	376.96MiB ≤ 430MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	missed_bytes	10/10	0B = 0B	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".

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
docker_containers_cpu	baseline	3	Crashed (exit code: 1)	Debug Dashboard
docker_containers_memory	comparison	0	Crashed (exit code: 1)	Debug Dashboard

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.