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AWS multi-region active-active architecture is a distributed cloud design where two or more AWS regions simultaneously handle live production traffic, supported by continuous cross-region replication and automated global traffic routing.
If one Region experiences service impairments, the others continue serving users without any failover delay. The remaining Regions are sized to handle full application load, ensuring continuity during disruptions. Users get routed to the closest Region via Route 53 latency-based routing or Global Accelerator, minimizing latency and delivering a faster experience.
This guide will demonstrate the AWS multiple region setup, and you’ll learn end‑to‑end deployment, data layer design, conflict resolution, monitoring, and how to avoid costly mistakes.
Multi-Region AWS architectures can cost 2–3× a single-Region equivalent when data replication, so before diving into implementation, you can take a view at the following scenarios to consider if you actually need this architecture.
Infrastructure is easy. AWS gives you Route 53, Global Accelerator, and CloudFront out of the box. But multi-Region active-active forces you to confront the CAP theorem head-on. In the face of network partitions between Regions, you will choose:
Now you can follow the steps below to configure a multi-region, active-active architecture on AWS.
Your users need to reach the nearest healthy Region. AWS offers three complementary approaches.
► DNS-Based Routing with Amazon Route 53
Route 53 serves as the entry point. Use latency-based routing to direct users to the closest Region. Each regional endpoint gets a health check; when a Region fails, Route 53 automatically stops routing traffic there.
Key configuration details:
1. Create a health check for each Region’s ALB with a 10-second interval and a failure threshold of 2
2. Set DNS TTL low (60 seconds) for faster failover.
3. Use EvaluateTargetHealth: true so Route 53 respects ALB health status
# Create a health check for a regional ALB
aws route53 create-health-check \
--caller-reference "us-east-1-health-$(date +%s)" \
--health-check-config '{
"Type": "HTTPS",
"FullyQualifiedDomainName": "us-east-1-alb.example.com",
"Port": 443,
"ResourcePath": "/health",
"RequestInterval": 10,
"FailureThreshold": 2
}'
►Accelerating Traffic with AWS Global Accelerator
Global Accelerator provides static anycast IP addresses that route traffic to the nearest healthy regional endpoint. Unlike DNS-based routing, Global Accelerator operates at the network layer and routes traffic over AWS’s private backbone, improving TCP/UDP latency by up to 60% compared to internet routing.
Each listener can have multiple endpoint groups (one per Region), and Global Accelerator routes traffic to the nearest healthy group. Use traffic dials to control the percentage of traffic sent to each Region—useful for gradual failover or canary deployments.
►Edge Caching with Amazon CloudFront
For content-heavy applications, CloudFront caches static assets at edge locations worldwide, reducing load on origin servers and improving user experience. Combine CloudFront with Route 53 latency-based routing for optimal performance.
You need data stores that handle multi-Region writes with acceptable consistency guarantees. Here are two options.
►Option 1: DynamoDB Global Tables (True Multi‑Master)
DynamoDB Global Tables provide fully managed multi-active replication across AWS Regions. You can write to any replica table, and changes automatically propagate to all other Regions. Global Tables use DynamoDB Streams under the hood to replicate changes between Regions.
While tens of thousands of customers successfully use DynamoDB Global Tables with eventual consistency, critical applications like payment processing systems and financial services demand more. For these applications, customers require zero Recovery Point Objective (RPO) during rare Region-wide events.
Multi-Region Strong Consistency (MRSC): In June 2025, DynamoDB Global Tables introduced Multi-Region Strong Consistency (MRSC), enabling zero RPO for high-availability multi-Region applications. MRSC global tables replicate your DynamoDB tables automatically across your choice of AWS Regions to achieve fast, strongly consistent read and write performance.
MRSC Availability by Region: MRSC is available in the following AWS Regions: US East (N. Virginia, Ohio), US West (Oregon), Europe (Ireland, London, Paris, Frankfurt), and Asia Pacific (Tokyo, Seoul, Osaka).
MRSC Architecture Requirements: MRSC requires three AWS Regions to maintain quorum. You can configure this in two ways:
(1) three full replicas
(2) two replicas plus a witness.
The witness Region contains only replicated change data without maintaining a full table copy, providing the required availability without the full storage cost.
Conflict Resolution: Global Tables with eventual consistency use Last Writer Wins (LWW) based on timestamps. With MRSC, strong consistency eliminates write conflicts entirely.
Cost: MRSC global tables are billed according to current Global Tables pricing. The Global Tables portion of a budget active-active setup runs about $18/month for modest workloads.
►Option 2: Aurora Global Database (For Relational Workloads)
Aurora Global Database replicates an Aurora cluster across up to six AWS Regions. One Region is primary (accepting reads and writes), while secondary Regions serve reads.
The Catch: Aurora Global Database does NOT support multiple writer nodes. All writes must go to the primary Region. For true active-active writes, you need write forwarding from secondary Regions to the primary—adding latency for write operations originating far from the primary.
Replication Lag: Aurora Global Database typically maintains cross-Region replication lag under 1 second, making it suitable for read-heavy workloads where users in different Regions need fast local access to data.
Cost: Aurora Global Database replication overhead adds approximately $85–100/month for a mid-size application.
►Option 3: Aurora DSQL (True Active-Active SQL)
Amazon Aurora DSQL is a serverless distributed SQL database (PostgreSQL-compatible) with virtually unlimited scale, highest availability, and zero infrastructure management. Key features:
How DSQL Achieves Multi-Region Strong Consistency: Aurora DSQL multi-Region clusters use synchronous cross-Region replication to maintain strong consistency between Regions (and between the DSQL witness Region). DSQL can accept reads and writes to either regional endpoint, and thanks to Aurora DSQL’s strong consistency, a reader in Region A can immediately see a committed write in Region B and vice versa.
The Key Advantage: The application stack doesn’t even need to know it’s operating in a multi-Region active-active configuration. It can be completely ignorant of the other Region. The application does not need to perform any cross-Region coordination or messaging—DSQL handles that. This dramatically simplifies application design.
Availability SLA: 99.99% single-Region availability; 99.999% multi-Region availability.
Endpoint Routing for Multi-Region DSQL: Applications using Aurora DSQL multi-Region clusters should implement a DNS-based routing solution (such as Route 53) to automatically redirect traffic between Regions. Best practices recommend implementing application-level routing logic to manage regional failovers holistically.
►Option 4: S3 Cross-Region Replication (For Object Storage)
For user uploads and static assets, enable S3 Cross-Region Replication (CRR) . Every object uploaded to the source bucket automatically replicates to destination buckets in other Regions. Use S3 Multi-Region Access Points (MRAPs) to simplify accessing replicated data across Regions.
►Option 5: ElastiCache (Cache Invalidation Strategy)
Each Region maintains its own ElastiCache cluster. The challenge: cache invalidation must be coordinated across Regions. When data changes in one Region, cached entries in other Regions must be invalidated. Common approaches:
Data Layer Comparison Table
|
Service |
Active-Active Writes |
Consistency Model |
RPO |
Availability SLA |
Best For |
|
DynamoDB Global Tables (MRSC) |
Yes |
Strong |
Zero |
99.999% |
NoSQL, key-value workloads, zero RPO |
|
Aurora Global Database |
No (write forwarding) |
Strong |
< 1 sec |
99.99% |
Relational, read-heavy workloads |
|
Aurora DSQL |
Yes |
Strong (ACID) |
Zero |
99.999% |
Relational with multi-Region writes |
|
S3 CRR |
N/A |
Eventual |
Minutes to hours |
99.99% |
Object storage, user uploads |
Deploy same infrastructure in every region using CloudFormation/Terraform. Each region must support complete global traffic during failover.
# CloudFormation Template (deploy to all regions)
AWSTemplateFormatVersion: '2010-09-09'
Description: Active-Active App Stack
Parameters:
Region: {Type: String, AllowedValues: [us-east-1, eu-west-1]}
Resources:
AppAutoScalingGroup:
Type: AWS::AutoScaling::AutoScalingGroup
Properties:
MinSize: 2, MaxSize:10, DesiredCapacity:3
VPCZoneIdentifier: [!Ref PrivateSubnet1, !Ref PrivateSubnet2]
LaunchTemplate: {LaunchTemplateId: !Ref AppLaunchTemplate, Version: !GetAtt AppLaunchTemplate.LatestVersionNumber}
TargetGroupARNs: [!Ref AppTargetGroup]
AppLaunchTemplate:
Type: AWS::EC2::LaunchTemplate
Properties:
LaunchTemplateData:
ImageId: !FindInMap [RegionMap, !Ref "AWS::Region", AMI]
InstanceType: c5.xlarge
UserData:
Fn::Base64: !Sub |
#!/bin/bash
aws s3 cp s3://deploy-bucket/app-latest.tar.gz /opt/app/
cd /opt/app && tar xzf app-latest.tar.gz
export AWS_REGION=${AWS::Region}
export APP_ROLE=active
systemctl start myapp
Users may switch regions between requests—sessions must be globally accessible. Use DynamoDB Global Tables with 24‑hour TTL.
import boto3, uuid, time
dynamodb = boto3.resource('dynamodb')
def create_session(user_id):
session_id = str(uuid.uuid4())
sessions_table.put_item(Item={
'session_id': session_id, 'user_id': user_id,
'created_at': int(time.time()), 'ttl': int(time.time()) + 86400
})
return session_id
def get_session(session_id):
response = sessions_table.get_item(Key={'session_id': session_id}, ConsistentRead=False)
return response.get('Item')
Concurrent cross‑region writes cause conflicts. Use one of these proven patterns:
1. Last‑Writer‑Wins: Default for DynamoDB Global Tables
2. Region Affinity: Assign each user a “home region” for writes; reads anywhere
3. CRDTs: Conflict‑free replicated data types for clean merges
While AWS native services like DynamoDB Global Tables and Aurora DSQL provide excellent active-active capabilities within the AWS ecosystem, many enterprises face scenarios where AWS-native solutions alone cannot meet all their requirements.
If you want an easier way to operate or need heterogeneous database replication, Info2Soft’s i2Stream offers a compelling alternative approach.
i2Stream is an enterprise-grade database replication software that provides real-time data synchronization, disaster recovery, migration, and integration for both homogeneous and heterogeneous databases. Unlike AWS-native services that work primarily within the AWS ecosystem, i2Stream is designed for diverse environments: on-premises, AWS, and other cloud providers.
Key capabilities of i2Stream:
AWS multi-region active-active architecture delivers AWS’s highest resilience level. Start with DynamoDB Global Tables for key‑value workloads or Aurora Global Database for relational data. Use Route 53 for low‑latency routing, deploy identical regional stacks via IaC, enforce stateless apps, and implement robust conflict resolution.
Alternatively, you can also choose Info2Soft’s i2Stream to set up your active-active architecture. It offers an easier way to replicate database across different regions. And its heterogeneous replication capability allows you to replicate data between different database platforms.
