local-first | data syncing, storage, and collaboration. that works | Data Processing library

You're not chaining these Observables here - thus an error from the API Observable will not propagate down the stream to the view layer. (moreover I'm not sure how Room operate but you will query it twice for the DB updates)

If I understands correctly, db.dEventDataStore().getAll() created by Room so this Flowable is infinite, listen to DB changes and emit any change. so you want to query server, and in case of data update the DB and expect emission from Room's DB Flowable.

in this case, you can do this in parallel using merge, and the API Maybe, pass through just the errors by ignoring any elements it's emit. in this way the downstream we'll get the data emissions only from Room DB, while still getting server error notifications.