Disaster Recovery
Disaster Recovery (DR) focuses on restoring Jenkins after major failures that exceed normal backup-and-restore scenarios.
What Qualifies as a Disaster​
Disaster scenarios include:
- Data center or cloud region outage
- Complete controller loss
- Storage corruption
- Security breach requiring full rebuild
- Accidental mass deletion
DR assumes infrastructure is unavailable.
Backup vs Disaster Recovery​
| Aspect | Backup | Disaster Recovery |
|---|---|---|
| Scope | Single system | Entire environment |
| Speed | Minutes–hours | Hours–days |
| Infra dependency | Existing infra | New infra |
| Planning | Often ad-hoc | Mandatory |
Backups alone are not DR.
Recovery Objectives​
Define clearly:
- RPO (Recovery Point Objective) – acceptable data loss
- RTO (Recovery Time Objective) – acceptable downtime
Business requirements drive DR design.
DR Architecture Patterns​
Common patterns:
- Cold standby (most common)
- Warm standby
- Active-active (rare for Jenkins)
Cold standby balances cost and reliability.
Cold Standby Strategy (Typical)​
- No running secondary controller
- Backups stored off-site
- Automated provisioning scripts ready
- Restore executed during disaster
Most teams use this model.
DR Readiness Checklist​
Ensure:
- Backups stored cross-region
- Restore scripts documented
- Plugin lists preserved
- Credentials securely recoverable
- DNS / load balancer changes documented
DR Execution Flow​
High-level flow:
- Declare disaster
- Provision new environment
- Install Jenkins core
- Restore from latest safe backup
- Validate system
- Redirect traffic
Speed depends on preparation.
Security Considerations During DR​
- Rotate credentials after restore
- Audit access logs
- Assume compromise if security-related incident
DR is also a security event.
Testing Disaster Recovery​
Rules:
- Test DR at least annually
- Simulate region loss
- Measure RTO and RPO
- Improve gaps after tests
Untested DR is imaginary DR.
Common DR Failures​
- Backups in same region
- No restore automation
- Undefined RTO/RPO
- No ownership during incidents
Best Practices​
- Treat DR as mandatory
- Automate infrastructure provisioning
- Document DR runbooks
- Review DR annually
Interview Focus Areas​
- Backup vs DR difference
- RTO vs RPO
- Why active-active Jenkins is rare