For LoopBack3 there is a help topic describing how to stream DB changes to clients in realtime: https://loopback.io/doc/en/lb3/Realtime-server-sent-events.html
Does LoopBack4 support this feature or are there any alternatives in LoopBack4?
Hello from the LoopBack team :)
We don't support server-sent events (SSE) in LoopBack 4 yet. We are discussing messaging/eventing style APIs in GitHub issue #1884.
As for detecting and streaming DB changes to clients in realtime, the implementation in LB3 was picking up only changes made via the LoopBack application and a single Node.js process, which does not work once you start scaling your application beyond a single worker process (e.g. multiple worker processes managed by pm2 or Docker/Kubernetes based deployment). In my opinion, it's better to leverage database-specific mechanisms for receiving notifications about changes, for example PostgreSQL's triggers & LISTEN/NOTIFY, CouchDB's Change Notifications, etc.
Feel free to open a new GitHub issue to discuss your specific requirements and how to address them using LoopBack 4: https://github.com/strongloop/loopback-next/issues/new