Asked about The classic fundamentals
Explain eventual consistency.
An answer that works
Replicas converge over time rather than immediately, so a read straight after a write may return the old value. Most systems accept this in exchange for availability under partition. Whether it is acceptable depends on the data: fine for a comment count, not for an account balance.
Reading an answer is not being able to give one. The section that teaches this is The classic fundamentals, 6 hours of Distributed systems.
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