The mathematics of conflict-free replicated data types (CRDTs) guarantee that two replicas will achieve consistency after they have received all updates. If you ask two replicas the same question, they will give you the same answer. There’s a trick to how CRDTs accomplish this: they guarantee that the replicas reach the same internal state. That implies that any question – so long as it is deterministic and based only on the internal state – will yield consistent answers.
But there’s an issue with this way of solving the problem. ...
