Which statement accurately describes eventual consistency?

Which statement accurately describes eventual consistency?

• A. All reads reflect the most recent write.
• B. Writes require cross-node coordination.
• C. Nodes eventually converge to the same value over time, though reads may be stale temporarily.
• D. It guarantees immediate consistency across all nodes.

Answer: (C)

In distributed systems, eventual consistency means the system allows temporary divergence between replicas, but over time all replicas converge to the same value. This enables fast, local writes and avoids heavy synchronization across nodes, with the trade-off that a read may return stale data for a while before updates propagate. The statement that best fits this concept says that nodes eventually converge to the same value, even if reads can be stale for a period. Other options describe stronger guarantees that aren’t inherent to eventual consistency: immediate reads reflecting the latest write (strong consistency) or reads and writes requiring immediate global coordination (which defeats the purpose of eventual convergence). Likewise, claiming immediate consistency across all nodes is the opposite of what eventual consistency provides.

In distributed systems, eventual consistency means the system allows temporary divergence between replicas, but over time all replicas converge to the same value. This enables fast, local writes and avoids heavy synchronization across nodes, with the trade-off that a read may return stale data for a while before updates propagate.

The statement that best fits this concept says that nodes eventually converge to the same value, even if reads can be stale for a period. Other options describe stronger guarantees that aren’t inherent to eventual consistency: immediate reads reflecting the latest write (strong consistency) or reads and writes requiring immediate global coordination (which defeats the purpose of eventual convergence). Likewise, claiming immediate consistency across all nodes is the opposite of what eventual consistency provides.