What is the CDN node failover mechanism?

The CDN (Content Delivery Network) node failover mechanism is a system designed to ensure uninterrupted content delivery by automatically redirecting traffic to alternative nodes when a primary node fails or becomes unavailable. This mechanism enhances reliability and minimizes downtime for end users.

How it works:

1. Health Monitoring: The CDN continuously monitors the status of its nodes (e.g., latency, packet loss, or server errors).
2. Failure Detection: If a node fails to respond or shows degraded performance, the system marks it as "unhealthy."
3. Traffic Redirection: Requests originally routed to the failed node are automatically redirected to the nearest healthy node or a backup node in the same region.
4. Failback: Once the failed node recovers, the system gradually reintroduces it into the traffic distribution pool.

Example:
A user in Europe requests a video hosted on a CDN. The request is initially routed to a node in Frankfurt. If that node crashes due to a hardware issue, the CDN's failover mechanism detects the failure and reroutes the request to another available node in Paris or Amsterdam, ensuring seamless playback without user interruption.

For such scenarios, Tencent Cloud offers EdgeOne, a CDN service with built-in failover capabilities, real-time health checks, and intelligent traffic routing to ensure high availability and performance.