sometime before the next read, and can be scheduled at different instants: Read repair: The correction is done when a read finds an inconsistency. This slows down the read operation. Write repair: The correction takes place during a write operation slowing down the write operation. Asynchronous repair: The correction is not part of a read or write operation. Strong eventual consistency Whereas eventual consistency is only a liveness guarantee (updates will be observed eventually), strong eventual consistency (SEC) adds the safety guarantee that any two nodes that have received the same (unordered) set of updates will be in the same state. If, furthermore, the system is monotonic, the application will never suffer rollbacks. A common approach to ensure SEC is conflict-free replicated data types. See also ACID CAP theorem References Consistency models de:Konsistenz (Datenspeicherung)#Verteilte Systeme