Introduce agent.monitoring.metrics_period

[pkoutsovasilis]

What does this PR do?

This PR introduces agent.monitoring.metrics_period field

Why is it important?

I consider this PR important as it allows each user to control the sampling period of monitoring metrics according to them needs

Checklist

• My code follows the style guidelines of this project
  - [ ] I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in ./changelog/fragments using the changelog tool
  - [ ] I have added an integration test or an E2E test

Disruptive User Impact

None

How to test this PR locally

Spawn an agent with setting the config agent.monitoring.metrics_period

Related issues

• Closes https://github.com/elastic/ingest-dev/issues/2680

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[cmacknz]

Thanks, confirmed it works by reloading a standalone agent configuration and overriding it in a Fleet managed agent using a request like:

PUT kbn:/api/fleet/agent_policies/4d16de58-695b-42f2-a006-c9f2f51d7ccd
{
    "name": "Agent policy 1",
    "namespace": "default",
    "overrides": {
      "agent": {
        "monitoring": {
          "metrics_period": "5s"
        }
      }
    }
}

Also confirmed the metrics documents are actually arriving at a 5s interval when I made the change above.

[alexsapran]

Thank you very much for the prompt support

[elastic-sonarqube]

Quality Gate passed

Issues
2 New issues
1 Fixed issue
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[alexsapran]

@cmacknz should we backport this to 8.14?

[pierrehilbert]

As this is an enhancement and not a bug fix I would say we shouldn't.
On the other hand, this change is small enough to limit the risk and could accelerate its usage for our benchmark.
Will let @cmacknz decide on Monday what is the best option here.

[cmacknz]

Yes normally this wouldn't be backported. What problem does backport to 8.14 solve for us? It is small so if it solves a big enough problem we can backport it anyway.

[amitkanfer]

What problem does backport to 8.14 solve for us?

solves 2 problems IMHO:

• Will unblock a team member with a project we've been wanting to do for a long time now :)
• One of the biggest asks is to have a performance benchmark for Agent, this is asked everywhere - and having this fix in place will allow us to start working on it.

So if not a risk - I'm +1 for backporting it ASAP.

[cmacknz]

Backport: #5003