Why should message consumers be idempotent?
- A To improve throughput
- B Because at-least-once delivery means the same message may be processed more than once
- C To reduce memory usage
- D Because messages arrive out of order
Answer
Because at-least-once delivery means the same message may be processed more than once
Most queues guarantee at-least-once rather than exactly-once delivery, so processing a duplicate must not produce a second side effect.





