Disaster recovery
Disaster recovery (DR) refers to having business continuity during and after events that impact an Azure region, such as a natural disaster or hacking incident that terminates an entire Azure region.
DR for Azure SQL Database can be implemented through active geo-replication. An auto-failover group can be configured for Azure SQL Database and SQL Managed Instance as a business continuity solution. A failover group is designed to ease out the deployment and management of geo-replication databases at scale.
Active geo-replication
Active geo-replication uses Always On technology to asynchronously replicate data to a maximum of four readable secondaries in the same or any other Azure region. Active geo-replication is available across all performance tiers except Hyperscale. A typical active geo-replication environment is shown in Figure 9.17:
Figure 9.17: A typical active geo-replication environment
The DB 1 database is primarily...