Ingestion service

Go, net/http, gorilla/websocket, go-redis. Source: ingestion-service/.

Behaviour

• GET /ws/robot/{id} upgrades to a WebSocket. The id must match ^[a-z0-9][a-z0-9-]{0,63}$, otherwise the handshake fails with 400.
• Each connection is served by its own goroutine.
• One frame per 500ms per connection is accepted. Extra frames get {"ok":false,"error":"throttled"}. Invalid frames also consume the window, so garbage cannot bypass the throttle.
• A frame holds one packet object or an array of up to 5 packets. Decoding is strict: unknown fields, missing fields, out of range values, a robot_id that differs from the connection id and timestamps more than 30s in the future are rejected with the reason in the ack.
• Accepted packets gain ingested_at and are published to robot:telemetry:live.
• The service is stateless and scales horizontally behind any load balancer that supports WebSockets.

Simulator

cmd/simulator embeds hotel-fleet.json and opens one socket per robot. See How the simulation works for the design, constants and flags.

go run ./cmd/simulator -url ws://localhost:8080 -n 1000 -interval 1s

Tests

telemetry_test.go covers packet mapping and every rejection rule. server_test.go covers the handshake, invalid ids, the throttle window and error acks, using an in memory publisher and a fake clock.