AWS Global Accelerator (GA) & Route 53 Integration Documentation

1. Purpose of This Document

This document describes the end-to-end setup of AWS Global Accelerator (GA) integrated with multi-region Application Load Balancers (ALBs) and Amazon Route 53. It explains the architecture, configuration steps, routing behavior, traffic flow, and best practices from a Cloud Engineer perspective.

---

2. What is AWS Global Accelerator?

AWS Global Accelerator is a global networking service that improves application availability and performance by directing user traffic to the nearest healthy AWS Region using Anycast static IPs.

Key Characteristics

• 🌍 Global service (not region-specific)

• 📌 Provides two static Anycast IP addresses

• 🚀 Routes traffic at AWS Edge locations

• 🌐 Supports multi-region endpoints (ALB, NLB, EC2, Elastic IP)

• 🔁 Offers near-instant regional failover

ℹ️ Important: Global Accelerator is managed from US West (Oregon). This is only the control plane location and does not mean that application traffic flows through Oregon.

---

3. Architecture Overview

👤 User
→ 🌐 Route 53 (DNS)
→ ⚡ Global Accelerator (Anycast IP)
→ 🧭 Nearest AWS Edge Location
→ 📍 Closest Healthy Region
→ 🎯 Regional ALB
→ 🧩 ECS Services

---

4. Why Use a Single Global Accelerator for Multiple Regions

✅ Recommended Design

• ✅ One Global Accelerator per application

• 🗂 Multiple endpoint groups (one per AWS Region)

• 🎯 Each endpoint group contains the regional ALB

⭐ Benefits

• ⚡ Automatic latency-based routing

• 🔄 Fast and seamless regional failover

• 🧩 Simple and clean DNS configuration

• 💰 Lower operational overhead and cost

❌ What NOT to Do

• ❌ Do not create multiple Global Accelerators for the same application

• ❌ Do not use Route 53 latency routing with Global Accelerator

---

5. Global Accelerator Configuration Steps

Step 1: Create the Global Accelerator

• ➕ Create a new Global Accelerator

• 🔌 Listener protocol: TCP

• 🔐 Listener ports: 80 / 443 (based on ALB configuration)

• 💾 Save and note the GA DNS name and static IP addresses

---

Step 2: Create Endpoint Groups (One Per Region)

Example Regions:

• 🇮🇳 ap-south-1 (Mumbai)

• 🇸🇬 ap-southeast-1 (Singapore)

• 🇺🇸 us-east-1 (Virginia)

For each endpoint group:

• 🎚 Set traffic dial to 100%

• ❤️ Use default health check settings

---

Step 3: Add ALBs to Endpoint Groups

For each region:

• 🎯 Endpoint type: Application Load Balancer

• 📍 Select the ALB from the same region

• ⚖ Keep default weight unless traffic tuning is required

---

6. Security Group Considerations

• 🔒 Global Accelerator itself does not have a Security Group

• 🌍 Traffic reaches the ALB from AWS Edge locations

ALB Security Group Must Allow:

• 🔓 Inbound HTTP/HTTPS traffic from either:

  • 🌐 0.0.0.0/0 (simple but less restrictive)

  OR

  • 📄 AWS-managed Global Accelerator prefix list (recommended for tighter security)

---

7. Route 53 Configuration (DNS Setup)

✅ Correct Route 53 Record Setup

• 🏷 Record name: api

• 🧾 Record type: A (IPv4)

• 🔗 Alias: Yes

• ➡ Route traffic to: Alias to Global Accelerator

• 📛 Target: Global Accelerator DNS name

• 🧭 Routing policy: Simple routing

• ✅ Evaluate target health: Yes

• 🚫 Health check: Not required

ℹ️ Important Notes

• Route 53 always shows US West (Oregon) for Global Accelerator

• ✅ This is expected and correct behavior

• ❌ Do not select Latency, Geo, or Weighted routing

---

8. Why Simple Routing is Mandatory with Global Accelerator

Layer	Responsibility
🌐 Route 53	DNS resolution only
⚡ Global Accelerator	Latency routing & failover
🎯 ALB	Application load balancing

Using Route 53 latency routing together with Global Accelerator duplicates routing logic and is not recommended.

---

9. Traffic Flow Explanation

1. 👤 User resolves api.domain.com

2. 🌐 Route 53 returns the Global Accelerator IP address

3. 🧭 User connects to the nearest AWS Edge location

4. ⚡ Global Accelerator selects the closest healthy region

5. 🎯 Traffic is forwarded to the regional ALB

6. 🧩 ALB routes traffic to ECS service tasks

---

10. High Availability & Failover

• ❤️ Endpoint health is continuously monitored

• 🚨 If a region becomes unhealthy:

  • 🔀 Traffic is instantly routed to the next healthy region

• ⏱ No DNS TTL or propagation delay

---

11. AWS Global Accelerator – Traffic Capacity

⚡ Global Accelerator Capacity

• 🚀 Designed to handle millions of requests per second

• 🌐 Built on the AWS global edge network using Anycast IPs

• 📈 Scales automatically with traffic spikes

🎯 Application Load Balancer (Per Region – Approximate Soft Limits)

• 🔁 ~100,000+ requests per second

• 🔗 ~3,000 new connections per second

• 📡 ~100,000 active connections

ℹ️ Actual capacity depends on instance size, target type, and request patterns.

---

12. Conclusion

This architecture provides:

• 🌍 Global performance optimization

• 🛡 High availability and fast failover

• 🧩 Simple and reliable DNS management

• 📈 Highly scalable multi-region design

End of Document