Question

A company runs three microservices behind a single Application Load Balancer using the domain shop.example.com. Requests to /api/orders must reach the orders service, /api/inventory must reach the inventory service, and all other paths must reach a default web frontend service. Each service runs in its own target group. The networking team must implement this routing with the fewest ALB resources while ensuring unmatched requests always land on the frontend. Which configuration meets these requirements?

Accepted Answer

On a single HTTPS listener, add path-based routing rules for /api/orders and /api/inventory pointing to their target groups, and set the listener's default action to forward to the frontend target group.

Answer

Create three separate ALBs, one per target group, and use Route 53 weighted records to distribute traffic among them.

Answer

Create one listener rule per target group using host-based conditions on shop.example.com, and rely on rule priority to break ties for unmatched paths.

Answer

Use a single listener with a fixed-response default action and add path-based rules for all three services including the frontend.