Linux TrackLesson 15 of 16

Debugging Linux Production Incidents

Run a structured triage process for outage symptoms, root cause isolation, and safe recovery.

Simple Explanation

Debugging Linux Production Incidents is a practical Linux skill used daily to keep servers healthy, secure, and predictable under production load.

Why Do We Need It?

Technical Explanation

This lesson focuses on practical execution for Debugging Linux Production Incidents, including command sequencing, evidence gathering, and validation of fixes.

Linux Operations Flow
Observe
Metrics
Logs
->
Diagnose
Correlate
Prioritize
->
Recover
Fix
Verify

Commands / Syntax

bash
# Baseline health
uname -a
uptime
free -h
df -h

# Process and service checks
ps aux --sort=-%cpu | head
systemctl --failed
journalctl -p err -n 30 --no-pager

Hands-on

  1. Capture a baseline with uptime, free -h, and df -h.
  2. Check process pressure and identify top consumers.
  3. Inspect service state and recent error logs.
  4. Apply one focused mitigation for the primary issue.
  5. Re-check baseline and verify symptom recovery.
Tip
Implementation Tip

Document your command order in a runbook so incident handling stays consistent across engineers.

Debugging Scenario

Failure: Users report intermittent 5xx errors from a Linux-hosted API.

Interview Questions

Beginner

What is the first thing you check in a Linux incident?

Start with host health baseline: uptime, memory, disk, and service state. This narrows the problem space quickly.

Intermediate

How do you prove your fix worked?

Use before/after evidence: reduced errors, stable service status, and no recurring critical logs during observation.

Scenario-based

A service keeps restarting every few minutes. What do you do?

Check restart reason and exit code, inspect logs around each restart, and verify resource or dependency failures before changing config.

Summary

Debugging Linux Production Incidents is a core Linux operations capability for stable, secure, and resilient production systems.