> [!abstract] A consistency model where, if all updates stop, the system will eventually converge to a consistent state - but not immediately. ## Strong vs Eventual Consistency **Strong consistency** (like paying with cash): - Immediate guarantee - You hand over money, they have it, you don't **Eventual consistency** (like paying with card): - Theoretical future guarantee - Money will eventually move between accounts ## In Distributed Systems If all events stopped publishing, eventually all systems would have the same view of the world. ## Tradeoff There's no solution to avoid this in distributed systems - you must embrace eventual consistency. It's one of the tradeoffs of [[Event Driven Architecture]]. ## Sources [[x_Sources/Videos/Video - Build An Event Driven System - NDC Oslo 2024|Build An Event Driven System - James Eastham (NDC Oslo 2024)]]