DR for PaaS Services
Design disaster recovery for Azure SQL Database using geo-replication and auto-failover groups, and compare this with VM-level replication for stateful workloads.
DR for PaaS vs. IaaS
Disaster recovery for IaaS services (VMs) typically involves Azure Site Recovery to replicate the entire OS and data disks to a secondary region. PaaS services have different DR models because the underlying infrastructure is managed by Microsoft. For PaaS, DR is usually configured at the data layer — replicating the data to a secondary region while the platform itself spins up automatically.
Azure SQL Database: Built-In Redundancy
Azure SQL Database provides built-in high availability at the zone level within a single region. For cross-region DR, it offers two key capabilities: active geo-replication (readable secondary databases in up to four other regions) and auto-failover groups (automated failover with a single listener endpoint). These are configured at the database or server level without needing Azure Site Recovery.
# Create a geo-replication link:
az sql db replica create \
--resource-group myRG \
--server primarySqlServer \
--name myDatabase \
--partner-server secondarySqlServer \
--partner-resource-group secondaryRG