Eventual consistency is a consistency model used in distributed databases where data updates don’t immediately propagate to all copies, but given enough time without new updates, all copies will eventually become identical. When you write data to one location in the system, other locations might temporarily see old data, but they’ll all catch up eventually. This usually happens within milliseconds or seconds (although it can be longer during network issues or node failures).
This approach contrasts with strong consistency, where every read is guaranteed to return the most recent write immediately. With eventual consistency, the system prioritizes availability and performance over immediate accuracy. You’re accepting that different parts of your database might temporarily disagree about the current state of the data in exchange for faster operations and better fault tolerance.
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