What is Cassandra's eventual consistency and how does it handle conflicts?

Cassandra uses eventual consistency as its default model — all replicas will eventually agree on the same value, but reads might return stale data momentarily. Conflict resolution uses Last Write Wins (LWW): every write is timestamped (in microseconds), and the version with the latest timestamp wins. This means: if two clients write to the same cell simultaneously, the one with the later client timestamp "wins" — the other write is silently discarded. Read repair: when Cassandra reads from multiple replicas and detects inconsistency, it repairs stale replicas in the background (read_repair_chance). Anti-entropy repair: the nodetool repair command compares all replicas and synchronizes them — run regularly in production. Implications: LWW means clock skew between nodes can cause data loss. Using TIMESTAMP in writes allows client-side timestamp control. Cassandra is not suitable for operations requiring strong consistency without configuring QUORUM or ALL consistency levels.