Prometheus — Metrics

Prometheus

Time-series database for metrics. Scrapes targets every 15s.

Components

• node_exporter (10 MB) — OS metrics: CPU, RAM, disk, network
• cAdvisor (30 MB) — container metrics: CPU, RAM, restarts per container
• Prometheus (300 MB) — scrapes, stores, queries metrics

Config

scrape_configs:
  - job_name: node
    static_configs:
      - targets: ['test-node-exporter:9100']
  - job_name: cadvisor
    static_configs:
      - targets: ['test-cadvisor:8080']

Multi-Server

Add remote targets (via WireGuard VPN):

- targets: ['10.0.0.2:9100']   # remote node_exporter
- targets: ['10.0.0.2:8080']   # remote cAdvisor

On remote server: only install node_exporter + cAdvisor (~40 MB RAM).