Currently I'm using Socket.io / SignalR to emit an event from my backend message queue system, whenever new data is incoming. That way I can setup an event handler in my React application and update the relay cache from within the event handler.
It does not seem like the most Graphql ish way to do things, so I was playing a bit around with pre-RFC live queries implementations, where you observed data changes in reactive data stores pushed it to the graphql server, and further to the client using websockets... with some rather complex custom code... obviously graphql is not ready for real live queries (not polling)
A few lines further down it says:
When building event-based subscriptions, the problem of determining what should trigger an event is easy, since the event defines that explicitly. It also proved fairly straight-forward to implement atop existing message queue systems.
Which leads me to my question. How can you (in a graphql way) best trigger graphql subscriptions when a new event is incoming to your backend message queue application and you need to reflect this new data in the ui in realtime - let's say each second? I'm not talking about triggering the event in the frontend/client or polling ever x seconds like you usually see when talking about subscriptions.
Not sure it's relevant but I'm using Relay Modern as my preferred graphql client.
Here's some ideas that might work if I get a little help to understand in general how to trigger/call a subscription without a mutation.
Backend worker / message queue "A" receives new incoming event with some device data. It uses either SignalR, or other pubsub (redis/socket.io/?) to notify the graphql server "B" (which subscribes to the event) about a new event has happened. The graphql server then trigger/execute the subscription and the frontend react relay application "C" automatically updates, since it has a relay subscription defined. This would be ideal, right? but how to trigger subscription on the graphql server?
Simply use Socket.io/SignalR to emit events from backend worker / message queue "A" on incoming data, subscribe and handle the event in the frontend "B", and then programically calling the subscription from within the Socket.io/SignalR event handler (if such a thing, directly calling a subscription, is even possible?). But then the only improvement from using subscriptions, instead of pure Socket.io/SignalR will be that I have moved the updating of the relay cache/store from the handler to the subscription. Not a big improvement, if any. But the manual update of the cache/store is really cumbersome, although not that hard :/
How do people handle real streaming live (device) data with signalr, and why is all realtime articles/examples just repeating the same old simple chat application, where the ui just updates after a user makes a click event? Is graphql not suited yet for dealing with a stream of frequently incoming device data in realtime? I understand why live queries was delayed after playing with implementing them myself, but without them, REAL realtime data updates and push it from the server to the frontend?
