Best practices for Amazon DynamoDB Global Tables – Part 2: Failover strategies

This article covers failover strategies for Amazon DynamoDB Global Tables, comparing two primary approaches and operational considerations during regional disruptions.

• Route 53 Application Recovery Controller (ARC) provides seconds-to-minutes RTO with multi-service coordination
• Region switch orchestrates complex recovery tasks across multiple AWS accounts automatically
• Routing controls redirect traffic via DNS with extremely reliable data plane across five endpoints
• Safety rules prevent dangerous state changes and operator errors during high-stress incidents
• Readiness checks continuously verify standby replica matches production configuration and capacity
• DNS-based Route 53 failover offers simpler setup with several-minute RTO using CloudWatch alarms
• Composite alarms monitor multiple signals (5xx errors, SystemErrors, ReplicationLatency) for reliable failover
• After failover, expect stale data reads, conflict resolution surprises, and potential throttling
• MRSC removes RPO entirely for zero data loss requirements
• Mission-critical workloads should use ARC; straightforward architectures can start with DNS-based failover

Choose failover strategy based on workload criticality and RTO requirements, then validate with AWS Fault Injection Service before incidents occur.