AWS Global Accelerator handles network congestion primarily by routing user traffic onto the AWS global network, which is designed to be congestion-free and highly redundant. This approach avoids the often congested and less reliable public internet paths, thereby reducing packet loss, jitter, and latency, and improving overall application performance and availability.
Here are the detailed mechanisms by which AWS Global Accelerator manages network congestion:
**1. Leveraging the AWS Global Network:
Instead of routing traffic over the public internet, which can be congested and involve multiple hops, AWS Global Accelerator ingresses traffic at the AWS edge location closest to the user through static anycast IP addresses. From there, traffic travels over the AWS private global network, which is optimized for high performance and low congestion. This network is redundant and engineered to minimize delays and packet loss, ensuring a smooth and reliable path to the application endpoints hosted in AWS Regions[3][4][6][10].
**2. Intelligent Traffic Routing and Failover:
AWS Global Accelerator continuously monitors the health of application endpoints using TCP, HTTP, and HTTPS health checks. It dynamically routes user traffic to the closest healthy endpoint, automatically failing over to alternate endpoints if congestion or failures occur. This failover capability ensures traffic is directed away from congested or unhealthy paths, maintaining availability and consistent performance[4][11].
**3. Traffic Dials and Endpoint Weights for Fine-Grained Traffic Control:
To manage traffic distribution and avoid overloading any single endpoint or region, AWS Global Accelerator provides traffic dials and endpoint weights. Traffic dials allow you to control the percentage of traffic sent to specific endpoint groups (regions), which can be dialed down to relieve congestion or dialed up to ramp traffic gradually. Endpoint weights let you adjust traffic proportions among multiple endpoints within a region, enabling balanced load distribution and preventing congestion at any single endpoint[1][2][7][11].
**4. Multiple Network Zones and ISP Peering:
AWS Global Accelerator uses multiple isolated network zones, each with its own physical infrastructure and peering relationships with different ISPs. This design reduces the impact of ISP-specific congestion or outages by allowing traffic to be routed through alternative network zones and ISPs. Clients receive two static IP addresses from different network zones, providing redundancy and reducing the blast radius of network issues[8].
**5. Client Affinity and Stateful Routing:
For applications requiring session persistence, AWS Global Accelerator can maintain client affinity by routing all requests from a user to the same endpoint. This prevents the overhead and latency that can arise from switching endpoints mid-session, which could exacerbate congestion-related delays[4][11].
In summary, AWS Global Accelerator mitigates network congestion by moving user traffic onto a private, highly optimized global network, intelligently routing around congested or unhealthy endpoints, providing fine-grained traffic control to balance loads, and leveraging redundant network zones and ISP paths to maintain high availability and low latency. This results in improved application performance and reliability even under varying network conditions.
Citations:
[1] https://docs.aws.amazon.com/global-accelerator/latest/dg/introduction-how-it-works.html
[2] https://aws.amazon.com/blogs/networking-and-content-delivery/traffic-management-with-aws-global-accelerator/
[3] https://aws.amazon.com/global-accelerator/features/
[4] https://aws.amazon.com/global-accelerator/faqs/
[5] https://cloudchipr.com/blog/aws-global-accelerator
[6] https://cloudvisor.co/aws-guides/aws-global-accelerator/
[7] https://hands-on.cloud/aws-services/global-accelerator/
[8] https://aws.amazon.com/blogs/networking-and-content-delivery/measuring-aws-global-accelerator-performance-and-analyzing-results/
[9] https://www.nops.io/glossary/what-is-aws-global-accelerator/
[10] https://www.hava.io/blog/what-is-aws-global-accelerator
[11] https://digitalcloud.training/aws-global-accelerator/
[12] https://www.youtube.com/watch?v=Docl4julOQw