🧩Route-53

What is AWS Route 53?

AWS Route 53 is a scalable and highly available Domain Name System (DNS) web service. It performs three major functions:

1. Domain registration

2. DNS routing

3. Health checking

📦 Core Components of Route 53

🧰 Use Cases

🏗️ Architecture Diagram (Overview)

sqlCopyEditUser Request
    |
    v
Route 53
    |
    +-- Public Hosted Zone
    |     +-- A Record --> Application Load Balancer (EC2, EKS, etc.)
    |
    +-- Private Hosted Zone
          +-- Internal Services (e.g., *.internal.example.com)

⚙️ Workflow

Scenario: Deploying a Web App Using EC2 Behind ALB

1. Domain Registration (Optional):

   • Buy domain from Route 53 or transfer an existing one.

2. Create a Hosted Zone:

   • Public hosted zone for myapp.com.

3. Add DNS Records:

   • A Record → Alias to Application Load Balancer

   • CNAME → Used for subdomains like www.myapp.com

4. Attach Routing Policy:

   • Simple → For single target

   • Weighted → For blue-green deployments

   • Failover → For active-passive failover setup

   • Latency → For performance optimization

5. Health Check (Optional):

   • Monitor backend EC2 or endpoint

   • Route 53 will remove unhealthy resources from DNS response

🪜 Step-by-Step Setup (Example)

🎯 Objective: Route domain myapp.com to an Application Load Balancer

✅ Prerequisites:

• An EC2-based application behind an Application Load Balancer

• A registered domain name (e.g., from Route 53 or GoDaddy)

• IAM permissions to manage Route 53

🔧 Steps:

1. Create Hosted Zone

• Go to Route 53 → Hosted Zones

• Click Create Hosted Zone

• Choose type: Public Hosted Zone

• Enter domain name: myapp.com

2. Get NS Records

• Copy the Name Server (NS) records generated

• If domain is external, update nameservers at your registrar

3. Create A Record (Alias to ALB)

• In your hosted zone, create a new record:

  • Type: A – IPv4 address

  • Alias: Yes

  • Alias Target: Choose your ALB

  • Routing Policy: Simple / Weighted / Latency, etc.

  • TTL: 60 seconds (default)

4. Optional: Create CNAME Record

• www.myapp.com → myapp.com

5. Health Check (Optional)

• Create health check to monitor EC2 or endpoint.

• Attach health check to record for failover setup.

🚦 Routing Policy Examples

🏛️ Architecture Example: Multi-region Failover

lessCopyEdit[Client]
   |
   v
[Route 53]
   |
   +-- Health check: us-east-1 ALB
   |      |
   |      v
   |   [App in us-east-1]
   |
   +-- (Failover if unhealthy)
          |
          v
     [App in us-west-2]

⚠️ Best Practices

• Use alias records instead of hardcoding IPs for AWS resources.

• Use private hosted zones for internal services within a VPC.

• Set up health checks + failover for high availability.

• Use latency or geolocation routing for global apps.

• Monitor DNS TTL and propagation delays when updating records.

🧪 Real-Time Use Case (Blue-Green Deployment)

1. Deploy v1 of your app to blue.myapp.com (ALB1)

2. Deploy v2 to green.myapp.com (ALB2)

3. Weighted routing:

   • Blue = 90%, Green = 10%

   • Gradually shift traffic

4. Monitor health check

5. Update myapp.com alias to point fully to green when stable