Dealing with unreliable connections

[ignatz]

(context: TrailBase maintainer here)

I was recently thinking a bit more about providing stronger guarantees in the light of "event loss". The TrailBase integration is pretty naive, uses SSE and if it gets auto-reconnected state would likely diverge.

To my understanding electric also uses SSE (https://electric-sql.com/docs/api/http#server-sent-events-sse), which is generally pretty opaque when it comes to managing connection state. After taking a quick look at its current implementation, it's not clear to me if there's maybe some magic happening under the hood (e.g. invalidate and re-build state from scratch if sequence numbers get out of sync 🤷‍♀️). Does electric's integration offer any guarantees?

I was mostly wondering what the official stance is for:

• Are any guarantees pushed down to the transport?
• Even if the transport is reliable but gets fully disconnected, what's the best-practice to re-sync/fix-up collections on the developer's side?