Linux Foundation PCA Exam - Topic 3 Question 23 Discussion

The Prometheus Node Exporter is a core system-level exporter that exposes hardware and operating system metrics from *nix-based hosts. It collects metrics such as CPU usage, memory, disk I/O, filesystem space, network statistics, and load averages.

It runs as a lightweight daemon on each host and exposes metrics via an HTTP endpoint (default: :9100/metrics), which Prometheus scrapes periodically.

Key clarification:

It does not instrument applications (A).

It does not collect metrics directly from application HTTP endpoints (B).

It is unrelated to HTTP probing tasks --- those are handled by the Blackbox Exporter (D).

Thus, the correct use of the Node Exporter is to collect and expose hardware and OS-level metrics for Prometheus monitoring.

Extracted and verified from Prometheus documentation -- Node Exporter Overview, Host-Level Monitoring, and Exporter Usage Best Practices sections.