Message Ordering, Backpressure, and RabbitMQ DLQs on AWS
Quick summary: FIFO guarantees shrink throughput—and unbounded queues only move backpressure to your AWS bill. Ordering, flow control, and Amazon MQ dead-letter patterns vs Kinesis resharding.
Key Takeaways
- FIFO guarantees shrink throughput—and unbounded queues only move backpressure to your AWS bill
- Ordering, flow control, and Amazon MQ dead-letter patterns vs Kinesis resharding
- June 2026: SQS FIFO gives order within message group at 300 TPS/group scale—ordering has a throughput price
- What to do this week 1
- 2
Table of Contents
June 2026: SQS FIFO gives order within message group at 300 TPS/group scale—ordering has a throughput price. Standard queues maximize throughput without global order.
Ordering guarantees
| System | Guarantee |
|---|---|
| SQS FIFO | Per MessageGroupId |
| Kinesis | Per partition key |
| MSK | Per partition |
| RabbitMQ | Single active consumer per queue |
Backpressure
Producers faster than consumers → queue depth grows → latency and cost. Responses:
- Scale consumers (ECS/EKS HPA on custom metric
ApproximateNumberOfMessagesVisible) - Drop to DLQ with alarm threshold
- Rate limit producers at API Gateway
Amazon MQ (RabbitMQ) DLQ
Configure dead-letter exchange + TTL; mirror to CloudWatch via plugin/logs. Retry with exponential backoff—do not infinite requeue.
What to do this week
- Set
maxReceiveCounton SQS redrive policy. - Alarm queue age p99 > SLO.
- Document ordering requirements per event type—downgrade to standard where possible.
What this guide doesn’t cover
MSK EOS—part 1 of track.
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