Making Magic Transit health checks faster and more responsive

Cloudflare has improved its Magic Transit GRE tunnel health check system, resulting in a more stable experience for customers and significantly reducing CPU and memory usage at its edge locations. The new system involves consistent hashing to assign tunnels to servers, allowing them to frequently check the weather for a few tunnels and share overall weather reports without overwhelming workloads. This led to over 70% reduction in CPU usage and nearly 85% decrease in memory usage.