Support expected_tags_duration for journald logs

[gh123man]

What does this PR do?

This PR adds support for logs_config.expected_tags_duration to journald log sources. When this setting is configured, host tags will be attached to logs for the configured period of time.

Motivation

Additional Notes

Possible Drawbacks / Trade-offs

Describe how to test/QA your changes

1. Install the agent on a linux system with systemd (ubuntu works)
2. configure journald log collection
3. configure logs_config.expected_tags_duration to some value like: 1m
4. configure tags: foo:bar in the datadog.yaml to add some host tags
5. Run the agent and start agent stream-logs
6. Before the timeout is reached, emit some logs to journald (systemd-cat echo "Hello Journal"). Confirm that the tags foo:bar are present.
7. After the timeout as expired, emit more logs and confirm the host tags are no longer present on the log messages.

[pr-commenter[bot]]

Bloop Bleep... Dogbot Here

Regression Detector Results

Run ID: 1764ad30-f933-425e-a325-b891ed6fcc81 Baseline: 9507b468677e32a2f1b6130e9273ca195085dae3 Comparison: 8e71d9b8c5368fa60682ac98ef3bba97e6ed9fc3

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	+1.43	[-5.18, +8.04]

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	file_to_blackhole	% cpu utilization	+1.43	[-5.18, +8.04]
➖	file_tree	memory utilization	+0.40	[+0.30, +0.50]
➖	otel_to_otel_logs	ingress throughput	+0.30	[-0.35, +0.96]
➖	process_agent_real_time_mode	memory utilization	+0.26	[+0.22, +0.30]
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+0.12	[-1.34, +1.58]
➖	trace_agent_json	ingress throughput	+0.03	[+0.01, +0.06]
➖	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_msgpack	ingress throughput	-0.01	[-0.02, +0.00]
➖	process_agent_standard_check	memory utilization	-0.21	[-0.25, -0.17]
➖	tcp_syslog_to_blackhole	ingress throughput	-0.28	[-0.34, -0.22]
➖	process_agent_standard_check_with_stats	memory utilization	-0.52	[-0.55, -0.49]
➖	idle	memory utilization	-0.72	[-0.76, -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".

[gh123man]

/merge

[dd-devflow[bot]]

:steam_locomotive: MergeQueue

Pull request added to the queue.

This build is next! (estimated merge in less than 27m)

Use /merge -c to cancel this operation!