An application relies on an Amazon SQS queue for asynchronous processing. The application's design requires that messages are processed exactly once and in the order they are sent, even during high-throughput scenarios. The SysOps Administrator needs to configure the SQS queue to meet these strict requirements while minimizing operational overhead. Which SQS queue type and configuration should be used?
- AStandard Queue with a visibility timeout of 30 seconds.
- BFIFO Queue with content-based deduplication enabled.
- CFIFO Queue with a message group ID for ordered processing.
- DStandard Queue with long polling enabled.
Show answer & explanationAnswer & explanation
Correct answer: C. FIFO Queue with a message group ID for ordered processing.
FIFO (First-In, First-Out) queues guarantee message ordering and exactly-once processing. A message group ID is essential within a FIFO queue to ensure that messages belonging to the same group are processed strictly in order. Content-based deduplication helps with exactly-once delivery by preventing duplicate messages with identical body content.
Why the other options are wrong
- A. Standard queues do not guarantee ordering or exactly-once processing.
- B. While FIFO queues and content-based deduplication contribute to the requirements, the critical component for ordered processing *within groups* is the message group ID.
- D. Long polling reduces costs and empty responses but does not guarantee ordering or exactly-once processing for a Standard queue.
SQS FIFO Queues & Message Group ID
Amazon SQS FIFO (First-In, First-Out) queues guarantee processing of messages in the exact order they are sent and exactly once. A Message Group ID ensures that messages with the same group ID are processed in order, even if there are multiple consumers.
- Guarantees message ordering and exactly-once processing.
- Supports message group IDs for ordered processing of related messages.
- Throughput is lower than Standard queues (up to 3,000 messages/second with batching).
- Used for critical applications where order and uniqueness are paramount.
Memory trick: FIFO for order, Group ID for the flow, Content Dedupe for no repeat show!