Why Lowering ndots Breaks Alpine Pods (But Not Debian) — A Deep Dive into glibc vs musl Resolvers

If you're running Alpine-based pods in Kubernetes and someone tells you to lower ndots for better DNS performance — don't. Or at least, read this first. We had 5 DNS queries firing for every external domain lookup. The fix seemed obvious: drop ndots:5 to ndots:2 . An AI reviewer warned me it might break internal service resolution. The reasoning didn't hold up when I read the resolver code, so I went ahead — and broke things in a way I didn't expect. The AI was right about the symptom but wrong