An order-processing queue must guarantee messages are processed exactly once and strictly in the order sent. Which SQS configuration is required?
A.Standard queue with a long visibility timeout
Standard queues offer at-least-once delivery and best-effort ordering only.
B.Standard queue with message timers
Message timers delay delivery; they don't add ordering or deduplication.
C.FIFO queue with content-based deduplication or message deduplication IDs
Correct. FIFO + deduplication IDs gives ordering and exactly-once semantics.
D.Two standard queues chained together
Chaining queues doesn't create ordering guarantees.
Why this answer
Only FIFO queues preserve strict ordering and provide exactly-once processing via deduplication — either content-based (SHA-256 hash of the body) or explicit MessageDeduplicationId values.
Correct answer: C · Last reviewed 2026-10-26
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