Incident-Response

Introduction Chaos Engineering is the discipline of experimenting on a system to build confidence in the system’s capability to withstand turbulent conditions in production. Rather than waiting for failures to happen, chaos engineering proactively injects failures to identify weaknesses before they impact users. Why does this matter? In modern distributed systems (microservices, cloud infrastructure, containers), failures are inevitable. A network can partition, a server can crash, a database can slow down. Traditional testing can’t predict all the ways these components interact when things go wrong. Chaos engineering fills this gap by deliberately causing failures in a controlled way. …

Introduction An on-call runbook is a documented set of procedures and information that helps engineers respond to incidents effectively. A good runbook reduces Mean Time To Resolution (MTTR), decreases stress, and enables any team member to handle incidents confidently. Why Runbooks Matter Without Runbooks Every incident requires figuring things out from scratch Tribal knowledge lost when team members leave New team members struggle with on-call Inconsistent incident response Higher MTTR and more user impact With Runbooks Standardized, tested response procedures Knowledge preserved and shared Faster onboarding for new team members Consistent, reliable incident response Lower MTTR and reduced stress Runbook Structure Essential Sections Service Overview - What the service does Architecture - Key components and dependencies Common Alerts - What triggers pages and how to respond Troubleshooting Guide - Diagnostic steps and solutions Escalation Procedures - When and how to escalate Emergency Contacts - Who to reach for help Rollback Procedures - How to revert changes Useful Commands - Quick reference for common tasks Complete Runbook Template # On-Call Runbook: [Service Name] **Last Updated:** YYYY-MM-DD **Maintained By:** [Team Name] **On-Call Schedule:** [Link to PagerDuty/Opsgenie] --- ## Service Overview ### Purpose [What does this service do? Why does it matter?] Example: "The Payment Service processes all customer payments including credit cards, PayPal, and gift cards. It handles ~500 transactions/minute and is critical for revenue generation. Any downtime directly impacts sales." ### Key Metrics - **Traffic:** [Requests per minute/hour] - **Latency:** [P50, P95, P99 response times] - **Error Rate:** [Typical error percentage] - **SLO:** [Availability and performance targets] ### Business Impact - **High Impact Hours:** [Peak times when incidents matter most] - **Estimated Revenue Impact:** [Cost per minute of downtime] - **Affected Users:** [Number/type of users impacted by outage] --- ## Architecture ### System Components ┌─────────────┐ ┌──────────────┐ ┌─────────────┐ │ API GW │─────▶│Payment Service│─────▶│ Database │ └─────────────┘ └──────────────┘ └─────────────┘ │ ├─────▶ Stripe API ├─────▶ PayPal API └─────▶ Fraud Detection …

Introduction A blameless postmortem is a structured review process conducted after an incident to understand what happened, why it happened, and how to prevent similar incidents in the future—without placing blame on individuals. Why Blameless? The Problem with Blame Traditional approach: Engineers fear being blamed Information is hidden or sanitized Root causes remain undiscovered Same incidents repeat Blameless approach: Psychological safety encourages honesty Full context emerges Systemic issues are identified Organization learns and improves Core Principle “People don’t cause incidents; systems do.” …