ExactlyOnce

Top Architect

Mar 31, 2022 · Backend Development

Message Deduplication and Exactly‑Once Semantics in RocketMQ

This article explains why RocketMQ guarantees at‑least‑once delivery, describes the three typical duplication scenarios, evaluates simple idempotent approaches, discusses transactional and non‑transactional deduplication solutions—including a Redis‑based method—and outlines their advantages, limitations, and practical recommendations for achieving exactly‑once processing in distributed systems.