Networking

CDN overlay network; BGP limitations; global DNS LB; IXP placement; edge+intermediary caching layers; DDoS shielding

Hierarchical resolution process; TTL trade-offs; DNS as eventually consistent KV store; DNS as SPOF; static stability principle

The 8 fallacies (Deutsch/Sun 1994): network reliable, latency zero, bandwidth infinite, network secure, topology fixed, one admin, transport free, homogeneous network; stamp coupling; distributed logging/transactions/contracts

HTTP/1.1 vs HTTP/2 vs HTTP/3 (QUIC); multiplexing; HOL blocking; connection management; relationship to REST

DNS LB, L4 (transport), L7 (application), service discovery, health checks, power of two choices, sidecar as client-side LB; stateless services as prerequisite for scale-out

East–west traffic governance: mTLS, service authorisation, evolution from libraries to eBPF; sidecar as reuse mechanism for operational concerns; orthogonal coupling; data-sinking sidecar for EDM legacy integration

TLS encryption (asymmetric key exchange + symmetric data), authentication (certificate chain, root CA), integrity (HMAC), handshake, certificate expiry risk

*Understanding Distributed Systems* — Roberto Vitillo

Zonal architecture critique, NCSC eight principles, service mesh + OAuth2 implementation stack