Disaster recovery keeps services and data available after catastrophic failures or disruptive events. In Azure, paired regions, availability zones, resilient storage, and database backups provide layers of protection rather than one heroic button. section 1.3.2 section 10.5
A practical recovery strategy combines several protections:
- Use paired Azure regions to support business continuity and switch services between regions when necessary. section 1.3.2
- Use availability zones to tolerate hardware failures, power outages, and similar infrastructure problems. section 1.3.2
- Rely on Azure SQL DB’s automatic full, differential, and transaction log backups for point-in-time restoration. section 10.5
- Compare database services carefully: PostgreSQL offers strong features but lacks active geo-replication, while Azure SQL DB better fits robust recovery requirements here. section 10.3.4
Banning Books ordering system
Banning Books receives weekly full backups, differential backups every few hours, and transaction log backups every 5–10 minutes. With 7–35 days of retention, depending on service tier, the ordering database can be restored to a chosen point within that window, reducing potential data loss. section 10.5
Figure 10.4 The Azure relational database selection represented as Banning Books
Use the database-selection comparison to weigh disaster recovery alongside cost, performance, and security. section 10.3.4
