[Metricbeat] Debug log level spams "Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics" repeatedly

[cmacknz]

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before opening a Github Issue. Your questions will reach a wider audience there,
and if we confirm that there is a bug, then you can open a new issue.

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Please include configurations and logs if available.

For confirmed bugs, please report:

• Version: 9.3.0-SNAPSHOT
• Operating System: MacOS Sequoia 15.7.1
• Steps to Reproduce:

metricbeat.config.modules:
  path: ${path.config}/modules.d/*.yml
  reload.enabled: false

metricbeat.modules:
- module: system
  metricsets:
    - cpu
  enabled: true
  period: 1s
  processes: ['.*']

output.elasticsearch:
  hosts: ["https://c56d4e76a3644ecca0e89485ab9caac9.es.us-central1.gcp.staging.elastic.cloud:443"]
  preset: balanced
  api_key: <REDACTED>

logging.level: debug

mage build
sudo ./metricbeat run -e --strict.perms=false -c ./metricbeat.yml

Will output a ridiculous amount of the following logs repeatedly

{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.555-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.555-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.555-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.555-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.555-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.6.0"}
{"log.level":"debug","@timestamp":"2025-10-10T17:24:56.556-0400","log.origin":{"function":"github.com/elastic/elastic-agent-system-metrics/metric/system/numcpu.NumCPUWithLogger","file.name":"numcpu/numcpu.go","file.line":47},"message":"Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics","service.name":"metricbeat","ecs.version":"1.

This was originally discovered inspecting elastic-agent diagnostics but is reproducible with the Metricbeat configuration attached here.

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[cmacknz]

https://github.com/elastic/elastic-agent-system-metrics/blob/e160bde6241e2c6cc089a42d1e72f99afeffe4e4/metric/system/numcpu/numcpu.go#L40-L53

func NumCPUWithLogger(logger *logp.Logger) int {
	count, exists, err := getCPU()
	if err != nil {
		logger.Debugf("Error fetching CPU count: %v", err)
		return runtime.NumCPU()
	}
	if !exists {
		logger.Debugf("Accurate CPU counts not available on platform, falling back to runtime.NumCPU for metrics")
		return runtime.NumCPU()
	}

	return count
}

[cmacknz]

Will be fixed by elastic/elastic-agent-system-metrics#266 and then bumping the dependency here.