Câu hỏi phỏng vấn Mạng máy tính

Your team is building a mobile app that calls three stateless backend services running behind a round-robin load balancer, with no shared session store (no Redis) in the budget. Users must stay logged in across requests that may hit any of the three instances. Which authentication approach best fits this constraint, and why?

You are building a stock-price dashboard. The browser clients only need to *receive* price updates pushed from the server (they never send data back over that channel), updates arrive every 1-2 seconds, and the app must run inside a corporate network where the proxy only reliably allows plain HTTP/HTTPS traffic. Which transport is the most appropriate choice?

Your organization is redesigning the global multi-region ingress and security architecture for an enterprise API platform. The security team mandates near real-time authorization revocation (under 5 seconds) across all regions, while platform metrics show that synchronous OAuth2 token introspection against the primary IdP region adds up to 200ms latency to regional requests and creates a cross-region single point of failure. Which architectural strategy best balances low latency, regional fault isolation, and the strict revocation mandate?

A team is considering replacing HTTP long polling with WebSockets for a high-traffic chat service deployed behind multiple load balancers. What is the most accurate assessment of the operational trade-off?