Replication lag refers to the difference in disk storage capacity between the leader and a follower, primarily affecting data durability

Replication lag is the time delay between a write operation being committed on the leader and that write being fully applied to a follower

Replication lag refers to the number of replicas that are operating near maximum capacity, causing the quorum size (w) to decrease

Replication lag is the period during which a follower must block all read queries due to holding a shared lock on the entire dataset