Introduce a Redis Pub/Sub (or Streams) event bus so message/presence events published on one gateway reach sockets on other gateways. Integrate @socket.io/redis-adapter AND an application-level deliver:device:{deviceId} channel. Gateways subscribe to channels for their locally-connected devices.
Acceptance criteria:
- Message sent via node A is delivered to a recipient on node B
- No sticky sessions required
- Bus failure degrades gracefully (local delivery still works)
Introduce a Redis Pub/Sub (or Streams) event bus so message/presence events published on one gateway reach sockets on other gateways. Integrate
@socket.io/redis-adapterAND an application-leveldeliver:device:{deviceId}channel. Gateways subscribe to channels for their locally-connected devices.Acceptance criteria: