5.1.3. AWS Global Accelerator

AWS Global Accelerator improves application performance and availability by routing user traffic over the AWS global network backbone to optimal application endpoints, bypassing public internet congestion.

Scenario: For global applications, relying on the public internet for traffic routing can lead to inconsistent performance and high latency due to network congestion and suboptimal routing paths. AWS Global Accelerator solves this problem.

AWS Global Accelerator is a networking service that improves the availability and performance of your applications with a static, fixed entry point (Anycast IP addresses).

Key Features of AWS Global Accelerator:

• Static Anycast IP Addresses: Provides two static public IP addresses that act as a fixed entry point for your application. Traffic from users is routed to the closest AWS Edge Location to these IP addresses.
• AWS Global Network Backbone: Traffic entering an AWS Edge Location is then routed over the high-speed, private AWS global network backbone to your application's endpoint in an AWS Region. This bypasses public internet congestion.
• Protocol Agnostic: Works with any protocol (TCP, UDP, HTTP/HTTPS), unlike CloudFront which is primarily for HTTP/S.
• Endpoint Health Checks: Performs health checks on your application endpoints and automatically reroutes traffic away from unhealthy ones.
• Traffic Dials: You can specify traffic dials to control how much traffic goes to each endpoint (e.g., for A/B testing or blue/green deployments).
• Endpoints and failover: Each endpoint group belongs to one Region and holds ALBs, NLBs, EC2 instances or Elastic IP addresses (endpoint weights split traffic within the group). When every endpoint in a group fails its health checks, traffic moves automatically to the healthy group(s) — no DNS change and no TTL to wait out.
• vs. Route 53 latency-based routing: Route 53 answers with a Regional endpoint's IP at DNS time, so failover waits on resolver caching and the IPs can change. Global Accelerator keeps the same two anycast IPs and reroutes at the network layer.
• Pricing: A fixed hourly fee per accelerator plus a per-GB Data Transfer-Premium (DT-Premium) on top of standard EC2 data transfer rates — the premium pays for carrying the traffic over the AWS backbone.
• Use Cases: Global gaming, IoT, voice/video over IP, applications that require static IP addresses at the edge, or any application needing improved global performance and availability.

Practical Implementation: Creating a Global Accelerator (Conceptual)

# 1. Create an Accelerator
ACCELERATOR_ARN=$(aws globalaccelerator create-accelerator \
  --name MyGlobalAppAccelerator \
  --ip-address-type IPV4 \
  --enabled \
  --query Accelerator.AcceleratorArn --output text)
echo "Accelerator ARN: $ACCELERATOR_ARN"

# 2. Create a Listener (e.g., for TCP port 80)
LISTENER_ARN=$(aws globalaccelerator create-listener \
  --accelerator-arn $ACCELERATOR_ARN \
  --port-ranges FromPort=80,ToPort=80 \
  --protocol TCP \
  --query Listener.ListenerArn --output text)
echo "Listener ARN: $LISTENER_ARN"

# 3. Create an Endpoint Group (e.g., in us-east-1, pointing to an ALB)
ENDPOINT_GROUP_ARN=$(aws globalaccelerator create-endpoint-group \
  --listener-arn $LISTENER_ARN \
  --endpoint-group-region us-east-1 \
  --endpoint-configurations '{"EndpointId":"arn:aws:elasticloadbalancing:us-east-1:123456789012:loadbalancer/app/my-alb/abcdef1234567890","Weight":100}' \
  --query EndpointGroup.EndpointGroupArn --output text)
echo "Endpoint Group ARN: $ENDPOINT_GROUP_ARN"

⚠️ Common Pitfall: Using Global Accelerator for caching web content. While Global Accelerator optimizes the network path, it does not cache content. CloudFront is the purpose-built service for content caching at the edge.

Key Trade-Offs:

• Content Caching (CloudFront) vs. Network Path Optimization (Global Accelerator): CloudFront is best for reducing latency for HTTP/S content by serving it from a nearby edge cache. Global Accelerator is best for reducing latency for any TCP/UDP application by optimizing the network route over the AWS backbone.

Reflection Question: How does AWS Global Accelerator, by routing user traffic over the AWS global network backbone via static Anycast IP addresses, fundamentally improve application performance and availability by bypassing public internet congestion and optimizing routing to the best application endpoints?