It’s always DNS . . . except when it’s not: A deep dive through gRPC, Kubernetes, and AWS networking | Datadog

This post details the investigation and resolution of a complex incident involving gRPC, Kubernetes, and AWS networking. It highlights how issues that initially appear to be DNS-related can stem from deeper networking problems, including connection tracking, reverse path filtering, and the interaction between different networking layers (Cilium, Kubernetes, AWS). The post emphasizes the importance of comprehensive visibility through tools like ENA metrics and VPC Flow Logs for diagnosing such issues.