We all share state in that we all exist within the same universe. But the universe has laws of causality, and Joe advocated that software should always maintain causal consistency.
A database is not needed for your example. You could replace it with an actor holding onto its own memory. But all mutations to that actor, which the other actors hold references to via their mailbox, are causally consistent and observable.
That is the premise of the talk I linked elsewhere.
A database is not needed for your example. You could replace it with an actor holding onto its own memory. But all mutations to that actor, which the other actors hold references to via their mailbox, are causally consistent and observable.
That is the premise of the talk I linked elsewhere.