Design a Disaster Recovery System

Functional Requirements:

• The system should automatically back up critical resources (e.g., databases, virtual machines, application servers) on a regular schedule.
• Support for both full and incremental backups.
• Ability to restore resources from backups to a specific point in time.
• Real-time or near real-time data replication to a secondary site for critical data.
• Automatic failover to a secondary site in case of primary site failure.
• Manual failover and failback options for planned maintenance or testing.
• Monitoring and alerting for backup, replication, and failover status.
• Role-based access control for managing disaster recovery operations.

Non-Functional Requirements:

• High reliability: System should minimize downtime and data loss (define RTO and RPO targets, e.g., RTO < 1 hour, RPO < 15 minutes for critical systems).
• Scalability: Should handle growth in data volume and number of resources without significant redesign.
• Security: All backup and replication data must be encrypted in transit and at rest. Access to backups should be restricted and auditable.
• Performance: Backup and replication processes should not significantly degrade the performance of production systems.
• Compliance: System should support compliance with relevant data protection standards (e.g., GDPR, HIPAA) as needed.
• Cost-effectiveness: Use cost-efficient storage and network resources, especially for long-term backup retention.
• Maintainability: System should be easy to configure, monitor, and update.