Idempotency vs Duplicate Orders: 5 Reliable Solutions After a Double‑Charge Mishap
The article explains that idempotency prevents the same operation from being executed twice, illustrates a real double‑charge bug, evaluates five concrete approaches—including Redis check‑then‑set, DB unique index, optimistic lock, Redis distributed lock, and a message deduplication table—details their failure conditions and suitable scenarios, and recommends combining Redis lock with a database unique index for the most robust protection.
