📌 Overview

In real-world systems, downtime is not an option. Cloud applications must survive instance failures, service outages, and even full regional failures.

In this blog, I’ll walk you through a hands-on AWS Multi-Region Disaster Recovery (DR) architecture that automatically shifts traffic to a secondary region without manual intervention.

This project simulates how enterprise systems survive regional outages.

🏗️ Architecture Diagram

🔧 Architecture Components

Primary Region (ap-south-1)

• Application Load Balancer (ALB)


• Auto Scaling Group (EC2 instances from AMI)


• Amazon RDS (Primary)


• Amazon EFS (Shared storage)

Disaster Recovery Region (us-east-1)

• Application Load Balancer (ALB)


• Auto Scaling Group (EC2 from copied AMI)


• Amazon RDS Read Replica


• Amazon EFS backup / replicated data

Global Services

• Amazon Route 53 (DNS Failover & Health Checks)
  ## 🔄 Disaster Recovery Flow

1. User traffic enters through Amazon Route 53
   


2. Route 53 routes traffic to Primary ALB (ap-south-1)
   


3. Health checks continuously monitor application health


4. On failure detection:
   
   
   
   
   • Route 53 redirects traffic to DR ALB (us-east-1)
     
   
   
   • Auto Scaling launches EC2 instances from copied AMI
   
   
   • RDS Read Replica is promoted to Primary
   
   
   
   


5. Application becomes available from DR region without manual intervention
   

📂 Implementation Details

Detailed, step-by-step implementation guides with screenshots and diagrams

are available in the /steps directory:

• EC2 & AMI creation


• ALB & Auto Scaling setup


• Route 53 DNS failover


• RDS cross-region replication & promotion


• EFS backup strategy

Step 1: EC2 & AMI Setup (Primary Region)

In this step, we launch an EC2 instance in the primary region

(ap-south-1) and deploy an NGINX application.

Objective

Launch an EC2 instance and prepare a reusable AMI for Auto Scaling and DR.

Why This Step?

• EC2 hosts the application


• AMI ensures consistent server configuration


• Enables fast recovery in another region

Services Used

• EC2


• AMI


• Security Groups

Implementation Steps

1️⃣ Launch EC2

• Region: ap-south-1


• AMI: Amazon Linux 2


• Instance type: t2.micro


• Security Group:
  
  
  
  
  • SSH (22)
  
  
  
  

  
  
  
  - HTTP (80)
  

  
  
  

  

  
  

2️⃣ Install Application

sudo yum install nginx -y

sudo systemctl start nginx

Verify Application

Open browser

http://<ec2-public-ip>

Create AMI

• EC2--> Action --> Create Image


• Name: primary-app-ami

OUTCOME

• Application is running


• AMI created for auto scalling and DR region

Step 2: ALB & Auto Scaling Setup

Objective

Ensure high availability and self-healing EC2 infrastructure.

Why This Step?

• ALB distributes traffic


• Auto Scaling replaces failed instances automatically

Services Used

• ALB


• Target Group


• Auto Scaling Group


• Launch Template

Implementation Steps

1️⃣ Create Target Group

• Type: Instance


• Protocol: HTTP


• Health check path: /
  git pull --rebase origin main

2️⃣ Create Application Load Balancer

• Internet-facing


• Select ALL AZs (Best Practice)


• Attach target group

3️⃣ Create Launch Template

• Use AMI from Step 1


• Select correct VPC Security Group

4️⃣ Create Auto Scaling Group

• Desired: 2


• Min: 1


• Max: 4


• Attach ALB

Outcome

• EC2 instances auto-heal


• Application always available

Step 3: Route 53 Failover Routing

Route 53 continuously monitors the health of the primary ALB

and redirects traffic to the DR region during failure.

Objective

Automatically route traffic to DR region during failure.

Why This Step?

• DNS-based failover


• No manual intervention needed

Services Used

• Route 53


• Health Checks


• ALB

Implementation Steps

1️⃣ Create Hosted Zone

Domain:

riteshdev.me

2️⃣ Create Health Check

• Endpoint: Primary ALB


• Path: /


• Failure threshold: 3

3️⃣ Create DNS Records

Primary Record

• Routing: Failover (Primary)


• Alias → Primary ALB


• Evaluate target health: Yes

Secondary Record

• Routing: Failover (Secondary)


• Alias → DR ALB

Outcome

• Traffic shifts automatically on failure

Step 4: RDS Disaster Recover

A cross-region read replica is maintained and promoted during

regional failure.

Objective

Protect application data using cross-region replication.

Why This Step?

• EC2 is stateless


• Database must survive region failure

Services Used

• RDS


• Cross-Region Read Replica

Implementation Steps

1️⃣ Create Primary RDS

• Region: ap-south-1


• Engine: MySQL


• Optional: Multi-AZ

2️⃣ Create Read Replica

• Region: us-east-1


• Continuous replication

3️⃣ Promote Replica (DR Test)

• RDS → Promote read replica

Outcome

• Near-zero data loss


• Production-ready DR database

🎯 Key Objectives

• Build highly available infrastructure across multiple Availability Zones and Regions


• Implement automatic DNS-based failover
  


• Enable stateless application recovery using AMIs and Auto Scaling


• Protect stateful data (RDS & EFS) against regional failures


• Validate DR using real failure simulations
  

🛠️ AWS Services Used

🌍 Regions Used

• 
  Primary Region: ap-south-1
  


• 
  Disaster Recovery Region: us-east-1
  

📁 Project Structure

aws-multi-region-dr/

│

├── architecture/

│   └── dr-architecture.png

│

├── steps/

│   ├── ec2-setup.md

│   ├── alb-asg.md

│   ├── route53.md

│   └── rds-dr.md

│

├── screenshots/

│

└── README.md

🔄 Disaster Recovery Flow

• User traffic enters through Route 53
  


• Primary Application Load Balancer (ALB) serves traffic from ap-south-1
  


• Route 53 continuously monitors application health
  


• On failure:
  
  
  
  
  • Traffic is automatically routed to the DR region
    
  
  
  • Auto Scaling launches EC2 instances from the copied AMI
    
  
  
  • 
    RDS Read Replica is promoted to primary database
  
  
  
  
  
  

✅ No manual intervention required

🧪 Failure Scenarios Tested

• Primary EC2 instance stopped


• Application (NGINX) service stopped


• Auto Scaling instance termination


• Route 53 failover validation


• RDS Read Replica promotion

➡ Result: Application remained accessible via the DR region

📊 RTO & RPO (Design Targets)

💡 Why This Project Stands Out

• Real production-style disaster recovery design
  


• Hands-on failure testing (not just theoretical concepts)
  


• Clean and modular documentation
  


• Covers both stateless (EC2) and stateful (RDS, EFS) components
  


• Strong interview-ready cloud project
  

This project simulates how enterprise systems survive regional outages.

🧠 Key Learnings

• Difference between EC2 failover vs RDS failover
  


• 
  DNS-based failover using Route 53


• Importance of AMI-based recovery
  


• Cross-region replication trade-offs
  


• Auto Scaling behavior during instance and service failures
  

🚀 Future Enhancements

• Infrastructure automation using Terraform
  


• CI/CD pipeline integration


• 
  CloudWatch alarms and notifications


• Centralized AWS Backup policies
  


• S3 cross-region replication

📣 About the Author

Ritesh


Aspiring Cloud & DevOps Engineer


Focused on building resilient, scalable, and secure AWS architectures

⭐ For Recruiters

This repository demonstrates:

• Cloud architecture design skills


• Disaster recovery planning and execution


• Operational and troubleshooting mindset


• Strong technical documentation practices

📌 Please explore the **/steps directory