A real-time trading dashboard streams updates over WebSocket connections from browsers worldwide. The team wants a single global anycast entry point that understands HTTP so it can route requests by URL path. Which load balancer should front the dashboard?
Show answer and explanation
Answer: B
The global external Application Load Balancer is an HTTP(S) proxy with a global anycast front end. It understands the HTTP Upgrade handshake that starts a WebSocket session, and it can route by host or path. Once upgraded, the connection stays open, and its idle lifetime is governed by the backend service timeout. The TCP/UDP and proxy Network Load Balancers forward connections at Layer 4 without HTTP awareness, and the internal passthrough balancer serves only private traffic inside one region.
Why the other options are wrong
- A. A regional TCP/UDP balancer passes packets without HTTP awareness. It cannot route by URL path or host, and it is regional rather than global.
- C. The internal passthrough balancer is for private traffic inside one region. Browsers on the internet cannot reach it, and it offers no HTTP-level routing.
- D. A proxy Network Load Balancer carries TCP but does not interpret HTTP, so path-based routing is not available. It is not the HTTP-aware front end this dashboard needs.