Explained: AWS Global Accelerator

The failover drill was supposed to take five minutes. At 2:00 a.m. the team failed the primary region on schedule, the Route 53 health check noticed within seconds, and the DNS answer flipped to the standby site exactly as designed. Twenty minutes later, the dashboards told a different story. Nearly half the clients were still connecting to the dead region. Nothing was misconfigured; every layer was doing exactly what it was built to do. The reco… Read More

Explained: CoreDNS

You deploy a new service to your Kubernetes cluster. The pods come up healthy. You open a shell inside one of them and try to reach another service by name — http://payments-service — and nothing happens. Timeout. You try the full name: http://payments-service.billing.svc.cluster.local . Still nothing. You try the service's ClusterIP directly, and it works fine. Something in the cluster is resolving names, but it's not resolving yours. If … Read More