Disaster Recovery Planning | Minimize Downtime
Plan for incidents with comprehensive disaster recovery procedures and testing. GitScrum tracks DR documentation, runbooks, and recovery exercises.
9 min read
Hope for the best, plan for the worst. GitScrum helps teams document recovery procedures, track DR testing, and ensure business continuity.
DR Fundamentals
Recovery Objectives
DEFINING RECOVERY TARGETS:
┌─────────────────────────────────────────────────────────────┐
│ │
│ KEY TERMS: │
│ │
│ RTO (Recovery Time Objective): │
│ Maximum acceptable downtime │
│ "We must be back online within X hours" │
│ │
│ RPO (Recovery Point Objective): │
│ Maximum acceptable data loss │
│ "We can lose at most X hours of data" │
│ │
│ ─────────────────────────────────────────────────────────── │
│ │
│ SERVICE CLASSIFICATION: │
│ ┌─────────────────────────────────────────────────────────┐│
│ │ Service Tier RTO RPO ││
│ │ ─────────────── ──── ────── ────── ││
│ │ Payment API 1 15 min 0 (none) ││
│ │ User Database 1 30 min 5 min ││
│ │ Main App 1 1 hour 1 hour ││
│ │ Analytics 2 4 hours 24 hours ││
│ │ Dev Environment 3 24 hours 1 week ││
│ │ Archive Storage 3 48 hours N/A ││
│ │ ││
│ │ Tier 1: Critical (immediate priority) ││
│ │ Tier 2: Important (restore after Tier 1) ││
│ │ Tier 3: Non-critical (can wait) ││
│ └─────────────────────────────────────────────────────────┘│
│ │
│ COST vs RTO: │
│ Shorter RTO = More expensive infrastructure │
│ Balance business needs with budget │
└─────────────────────────────────────────────────────────────┘
Disaster Scenarios
SCENARIO PLANNING:
┌─────────────────────────────────────────────────────────────┐
│ │
│ COMMON DISASTER SCENARIOS: │
│ │
│ INFRASTRUCTURE: │
│ • Cloud region outage │
│ • Database server failure │
│ • Network connectivity loss │
│ • DNS failure │
│ │
│ DATA: │
│ • Database corruption │
│ • Ransomware encryption │
│ • Accidental data deletion │
│ • Backup failure │
│ │
│ APPLICATION: │
│ • Bad deployment │
│ • Configuration error │
│ • Dependency failure │
│ • Resource exhaustion │
│ │
│ SECURITY: │
│ • Account compromise │
│ • DDoS attack │
│ • Data breach │
│ │
│ ─────────────────────────────────────────────────────────── │
│ │
│ FOR EACH SCENARIO: │
│ • Detection: How will we know? │
│ • Response: What do we do immediately? │
│ • Recovery: How do we restore service? │
│ • Communication: Who do we notify? │
│ • Post-incident: How do we prevent recurrence? │
└─────────────────────────────────────────────────────────────┘
DR Documentation
Recovery Runbooks
RUNBOOK STRUCTURE:
┌─────────────────────────────────────────────────────────────┐
│ │
│ DATABASE RECOVERY RUNBOOK: │
│ ┌─────────────────────────────────────────────────────────┐│
│ │ DR-RUN-001: Primary Database Recovery ││
│ │ ││
│ │ SCENARIO: ││
│ │ Primary database server is unavailable ││
│ │ ││
│ │ DETECTION: ││
│ │ • Monitoring alert: DB connection failures ││
│ │ • Application errors spike ││
│ │ • Health check failures ││
│ │ ││
│ │ IMMEDIATE ACTIONS (< 5 min): ││
│ │ 1. Verify DB is actually down (not false alarm) ││
│ │ 2. Check cloud status page ││
│ │ 3. Declare incident, start comms ││
│ │ ││
│ │ RECOVERY OPTIONS: ││
│ │ ││
│ │ OPTION A: Failover to replica (RTO: 15 min) ││
│ │ 1. Promote read replica to primary ││
│ │ aws rds promote-read-replica --db-id prod-replica ││
│ │ 2. Update connection string in secrets ││
│ │ 3. Deploy application with new connection ││
│ │ 4. Verify connectivity ││
│ │ ││
│ │ OPTION B: Restore from backup (RTO: 2 hours) ││
│ │ 1. Identify latest good backup ││
│ │ 2. Restore to new instance ││
│ │ aws rds restore-db-instance-to-point-in-time ... ││
│ │ 3. Update connection string ││
│ │ 4. Verify data integrity ││
│ │ ││
│ │ VERIFICATION: ││
│ │ ☐ Application health checks passing ││
│ │ ☐ Critical transactions working ││
│ │ ☐ Monitoring showing healthy ││
│ │ ││
│ │ CONTACTS: ││
│ │ DBA: @db-team (Slack), +1-555-DB-TEAM ││
│ │ On-call: PagerDuty escalation ││
│ │ AWS Support: Case priority Critical ││
│ └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘
DR Task Tracking
DR DOCUMENTATION TASKS:
┌─────────────────────────────────────────────────────────────┐
│ │
│ DR EPIC: │
│ ┌─────────────────────────────────────────────────────────┐│
│ │ DR-001: Disaster Recovery Documentation ││
│ │ ││
│ │ Goal: Complete DR coverage for all Tier 1 systems ││
│ │ Deadline: End of Q2 ││
│ │ ││
│ │ RUNBOOKS: ││
│ │ ├── DR-RUN-001: Database recovery ✅ ││
│ │ ├── DR-RUN-002: Application failover ✅ ││
│ │ ├── DR-RUN-003: CDN/DNS failover ⏳ ││
│ │ ├── DR-RUN-004: Cache recovery ⏳ ││
│ │ ├── DR-RUN-005: Queue recovery ☐ ││
│ │ └── DR-RUN-006: Third-party fallback ☐ ││
│ │ ││
│ │ SUPPORTING DOCS: ││
│ │ ├── DR-DOC-001: Contact list ✅ ││
│ │ ├── DR-DOC-002: Communication templates ⏳ ││
│ │ ├── DR-DOC-003: Service dependency map ✅ ││
│ │ └── DR-DOC-004: Backup verification log ✅ ││
│ │ ││
│ │ TESTS: ││
│ │ ├── DR-TEST-001: Database failover test ✅ ││
│ │ ├── DR-TEST-002: Full DR drill (quarterly) ☐ ││
│ │ └── DR-TEST-003: Tabletop exercise ⏳ ││
│ └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘
Testing DR
Test Types
DR TESTING APPROACHES:
┌─────────────────────────────────────────────────────────────┐
│ │
│ TESTING PROGRESSION: │
│ │
│ DOCUMENTATION REVIEW (Weekly): │
│ Verify runbooks are up to date │
│ Check contact information is current │
│ Low risk, low effort │
│ │
│ BACKUP VERIFICATION (Weekly): │
│ Verify backups completed successfully │
│ Test restore to non-production environment │
│ Verify data integrity │
│ │
│ COMPONENT TESTING (Monthly): │
│ Test individual recovery procedures │
│ Database failover │
│ Application restart │
│ │
│ TABLETOP EXERCISE (Monthly): │
│ Walk through scenario without taking action │
│ Identify gaps in procedures │
│ Team discusses "what would we do if..." │
│ │
│ PARTIAL DR DRILL (Quarterly): │
│ Actually execute recovery procedures │
│ Test in production-like environment │
│ Measure actual recovery time │
│ │
│ FULL DR DRILL (Annually): │
│ Simulate major disaster │
│ Recover all systems │
│ Business continuity validation │
└─────────────────────────────────────────────────────────────┘
DR Test Task
DR TEST EXECUTION:
┌─────────────────────────────────────────────────────────────┐
│ │
│ QUARTERLY DR DRILL: │
│ ┌─────────────────────────────────────────────────────────┐│
│ │ DR-TEST-Q2: Q2 Disaster Recovery Drill ││
│ │ ││
│ │ Date: April 15, 2024 (Saturday, 6 AM) ││
│ │ Scenario: Primary region unavailable ││
│ │ Scope: All Tier 1 services ││
│ │ ││
│ │ OBJECTIVES: ││
│ │ ☐ Validate failover to secondary region ││
│ │ ☐ Measure actual RTO vs target ││
│ │ ☐ Verify data integrity post-failover ││
│ │ ☐ Test communication procedures ││
│ │ ││
│ │ SCHEDULE: ││
│ │ 06:00 - Drill start, simulate outage ││
│ │ 06:05 - Detection and incident declaration ││
│ │ 06:15 - Begin failover procedures ││
│ │ 07:30 - Target: All services restored ││
│ │ 08:00 - Verification and wrap-up ││
│ │ 08:30 - Drill end, begin failback ││
│ │ ││
│ │ PARTICIPANTS: ││
│ │ • On-call team ││
│ │ • SRE lead (observer) ││
│ │ • Management (communication practice) ││
│ │ ││
│ │ SUCCESS CRITERIA: ││
│ │ • RTO met for all Tier 1 services ││
│ │ • No data loss beyond RPO ││
│ │ • Communication sent within 10 min ││
│ └─────────────────────────────────────────────────────────┘│
│ │
│ POST-DRILL: │
│ ┌─────────────────────────────────────────────────────────┐│
│ │ DR-TEST-Q2-RETRO: Drill Retrospective ││
│ │ ││
│ │ RESULTS: ││
│ │ RTO Target: 90 min | Actual: 85 min ✅ ││
│ │ RPO Target: 5 min | Actual: 3 min ✅ ││
│ │ ││
│ │ WHAT WENT WELL: ││
│ │ • Runbooks were accurate ││
│ │ • Team coordination was smooth ││
│ │ • Failover completed faster than expected ││
│ │ ││
│ │ WHAT NEEDS IMPROVEMENT: ││
│ │ • Communication template had wrong Slack channel ││
│ │ • Cache warmup took longer than documented ││
│ │ ││
│ │ ACTION ITEMS: ││
│ │ ☐ Update communication template ││
│ │ ☐ Add cache pre-warming to runbook ││
│ │ ☐ Schedule next drill for Q3 ││
│ └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘
Communication
Incident Communication
DISASTER COMMUNICATION:
┌─────────────────────────────────────────────────────────────┐
│ │
│ COMMUNICATION PLAN: │
│ │
│ INTERNAL (Immediate): │
│ • Slack #incident channel │
│ • PagerDuty escalation │
│ • Email to leadership │
│ │
│ EXTERNAL (Within 15 min): │
│ • Status page update │
│ • Twitter/social acknowledgment │
│ • Customer support briefing │
│ │
│ ONGOING (Every 30 min during incident): │
│ • Status page updates │
│ • Internal Slack updates │
│ │
│ ─────────────────────────────────────────────────────────── │
│ │
│ COMMUNICATION TEMPLATES: │
│ ┌─────────────────────────────────────────────────────────┐│
│ │ INITIAL NOTIFICATION: ││
│ │ ││
│ │ Subject: [INCIDENT] Service Disruption ││
│ │ ││
│ │ We are currently experiencing service issues. ││
│ │ Impact: [describe user impact] ││
│ │ Status: Investigating ││
│ │ Next update: 30 minutes ││
│ │ ││
│ │ ───────────────────────────────────────────────────── ││
│ │ ││
│ │ UPDATE: ││
│ │ ││
│ │ We have identified the issue and are working on ││
│ │ restoration. ││
│ │ ETA: [time estimate] ││
│ │ Next update: 30 minutes ││
│ │ ││
│ │ ───────────────────────────────────────────────────── ││
│ │ ││
│ │ RESOLUTION: ││
│ │ ││
│ │ Service has been restored. All systems operational. ││
│ │ Duration: [X hours Y minutes] ││
│ │ Root cause: [brief description] ││
│ │ Post-mortem will follow within 48 hours. ││
│ └─────────────────────────────────────────────────────────┘│
└─────────────────────────────────────────────────────────────┘