root-cause-analysis（根本原因分析）

Root Cause Analysis

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Root cause analysis (RCA) identifies underlying reasons for failures, enabling permanent solutions rather than temporary fixes.

When to Use

• Production incidents
• Customer-impacting issues
• Repeated problems
• Unexpected failures
• Performance degradation

Quick Start

Minimal working example:

Example: Website Down

Symptom: Website returned 503 Service Unavailable

Why 1: Why was website down?
  Answer: Database connection pool exhausted

Why 2: Why was connection pool exhausted?
  Answer: Queries taking too long, connections not released

Why 3: Why were queries slow?
  Answer: Missing index on frequently queried column

Why 4: Why was index missing?
  Answer: Performance testing didn't use production-like data volume

Why 5: Why wasn't production-like data used?
  Answer: Load testing environment doesn't mirror production

Root Cause: Load testing environment under-provisioned

Solution: Update load testing environment with production-like data

Prevention: Establish environment parity requirements

Reference Guides

Detailed implementations in the references/ directory:

Best Practices

✅ DO

• Follow established patterns and conventions
• Write clean, maintainable code
• Add appropriate documentation
• Test thoroughly before deploying

❌ DON'T

• Skip testing or validation
• Ignore error handling
• Hard-code configuration values