Hi, is there a way to enforce only 1 subscriber per cold observable? I'm looking at

subscriberOn(Schedulers.single())

but that obviously fails, when inside that chain somebody switches schedulers

What do you mean? Cold observables can have only 1 subscriber anyway. Consecutive subscriptions to the same cold observables result in new event streams.

its a big hard to articulate. I want to allow only 1 subscriber running per all instances of a givem observable sync() : Single<Unit>