Triage

Executive Summary Observability = see inside your systems: metrics (CPU, memory, I/O), logs (audit trail), traces (syscalls, latency). This guide covers: Metrics: node_exporter → Prometheus (system-level health) Logs: journald → rsyslog/Vector/Fluent Bit (aggregation) eBPF tools: 5 quick wins (trace syscalls, network, I/O) Triage: 5-minute flowchart to diagnose CPU, memory, I/O, network issues 1. Metrics: node_exporter & Prometheus What It Is node_exporter: Exposes OS metrics (CPU, memory, disk, network) as Prometheus scrape target Prometheus: Time-series database; collects metrics, queries, alerts Dashboard: Grafana visualizes Prometheus data Install node_exporter Ubuntu/Debian: …