What are some examples of causal consistency in distributed systems?

Can you explain what causal consistency means in distributed systems?

Causal consistency is a model that ensures operations that are causally related are seen by all nodes in the same order.

Can you give me an example of causal consistency in action?

Sure! Imagine two users updating a shared document. If User A comments on a section and User B replies, both users should see the comment before the reply.

What happens if one user sees the reply before the comment?

That would violate causal consistency, as it breaks the logical order of events. The reply should only be visible after the comment.

How does causal consistency differ from eventual consistency?

Causal consistency ensures that causally related updates are seen in order, while eventual consistency only guarantees that all updates will eventually be seen by all nodes.