How to use this tool

Multi-Region Failover — Guide

How to configure a multi-region failover strategy for your payment infrastructure, what each failover mode means, and how to deploy the generated Terraform.

What is this tool for?

Payment systems cannot afford extended downtime. A single-region outage — even a partial AWS AZ issue — can take your payment processing offline and breach SLA commitments with acquirers, card schemes, and enterprise customers.

This tool generates a complete Terraform configuration for multi-region failover across any two AWS regions. Select your primary and secondary regions, choose a failover mode, set your RTO target, and enable optional services like DynamoDB Global Tables, Aurora Global Database, and ElastiCache replication. The output includes Route 53 health checks, DNS failover records, and all supporting infrastructure.

Step-by-step walkthrough

Step 1 — Select primary and secondary regions
  1. Choose your primary region — the region your payment service normally runs in.
  2. Choose your secondary region — the failover target. For EU workloads, common pairs are eu-west-1 (Ireland) + eu-west-2 (London) or eu-west-1 + eu-central-1 (Frankfurt).
  3. Primary and secondary must be different regions. The tool prevents selecting the same region for both.
Step 2 — Choose failover mode and RTO
  1. Select Active-Active, Active-Passive, or Pilot Light. See the mode reference below for the trade-offs.
  2. Set your RTO target. The tool will warn you if your chosen mode cannot achieve the selected RTO.
Step 3 — Enable optional data services
  1. DynamoDB Global Tables: enable if you use DynamoDB for payment state or idempotency keys that must be consistent across regions.
  2. Aurora Global Database: enable if you have a relational settlement ledger on Aurora that must fail over with minimal data loss.
  3. ElastiCache: enable if you use Redis for session state or rate limiting that must persist across a failover.
Step 4 — Export and deploy the Terraform
  1. Click Copy Terraform or Export to get the configuration.
  2. Place it in your infrastructure repo. Run terraform init to download the AWS provider for both regions.
  3. Run terraform plan and review the resources before applying.
  4. Replace the placeholder project name, domain name, and any resource-specific variables before applying.

Failover modes explained

Active-Active
Traffic is routed to both regions simultaneously using Route 53 weighted routing. Lowest RTO (seconds), highest cost. Requires DynamoDB Global Tables for data sync.
Active-Passive
Primary region handles all traffic. Secondary is pre-provisioned but idle. Route 53 health checks trigger automatic failover. RTO: 1–5 minutes.
Pilot Light
Core infrastructure pre-built in secondary region but scaled to zero. On failover, Auto Scaling scales up. Lowest cost option. RTO: 5–15 minutes.

Key terms

RTORecovery Time Objective — the maximum acceptable time between a failure and full service restoration. Expressed in seconds or minutes. Defined in SLAs and acquirer agreements.
RPORecovery Point Objective — the maximum acceptable amount of data loss measured in time. If your RPO is 30 seconds, your replication must keep the secondary no more than 30 seconds behind the primary.
Route 53 Health CheckAn AWS health check that monitors an endpoint (HTTP, HTTPS, or TCP). Failures trigger DNS failover — Route 53 automatically updates DNS records to point to the secondary region.
DynamoDB Global TablesMulti-region, multi-active DynamoDB replication. Writes in either region are replicated to the other with sub-second convergence. Required for Active-Active deployments.
Aurora Global DatabaseAurora feature that replicates a database cluster to up to 5 secondary regions with typical replication lag under 1 second. The secondary can be promoted to primary in approximately 1 minute.
Weighted routingRoute 53 routing policy that distributes traffic to multiple endpoints by weight (percentage). Used in Active-Active mode to split traffic between regions.

Frequently asked questions

Ready to configure your failover strategy?
Select your regions, choose a mode, and export production-ready Terraform in minutes.