How to Plan Multi-Region Failover for Critical AWS Workloads

Retrospective: this article looks back at events from December 2021, written in 2026 with the benefit of hindsight.

Regional outages are rare but real. Here is how to plan multi-region failover for the AWS workloads that truly need it.

Step 1: Decide what needs multi-region

Classify workloads by recovery time objective (RTO) and recovery point objective (RPO). Multi-region active-active is expensive; most workloads need only backup and restore or pilot light.

AWS describes four common strategies:

• Backup and restore — cheapest, slowest (hours to days).
• Pilot light — core data replicated, minimal infrastructure running in the second region.
• Warm standby — scaled-down full environment running.
• Multi-site active-active — full capacity in multiple regions.

Step 2: Replicate data

• S3 Cross-Region Replication.
• DynamoDB global tables.
• Aurora Global Database or cross-region read replicas.
• AWS Backup cross-region copies.

Step 3: Make infrastructure reproducible

Use infrastructure as code (CloudFormation, Terraform, CDK) so the secondary region can be deployed identically.

Step 4: Plan for control plane unavailability

• Pre-provision capacity in the secondary region (warm standby) for critical workloads.
• Use Route 53 health checks and failover routing (Route 53's data plane is designed for high availability).
• Use Route 53 Application Recovery Controller for controlled failover.

Step 5: Replicate identity and secrets

IAM is global, but make sure KMS keys, Secrets Manager secrets and parameter values exist in the secondary region.

Step 6: Test

Run failover game days at least annually. Measure actual RTO and RPO against targets.