How do you ensure data consistency in Amazon RDS across multiple Availability Zones or regions?
To ensure data consistency in Amazon RDS across multiple Availability Zones or regions, use the Multi-AZ deployment feature. This automatically replicates data synchronously to a standby instance in another AZ using synchronous replication. In case of failure, RDS performs automatic failover to the standby instance, minimizing downtime and maintaining consistency.
For cross-region replication, use Read Replicas with asynchronous replication. Create Read Replicas in different regions and enable global tables for multi-region applications. Monitor replica lag to maintain acceptable levels of consistency.
Use AWS Database Migration Service (DMS) for ongoing replication between source and target databases across regions, ensuring consistent data during migration.
Implement application-level consistency checks by periodically comparing data hashes between primary and secondary instances, identifying discrepancies, and resolving them accordingly.
