Best practices for quorum queues for Amazon MQ for RabbitMQ
We recommend using the following best practices to improve performance when working with quorum queues.
Handling poison messages by setting a delivery limit
Poison messages occur when a message fails and is redelivered multiple times.
You can set a message delivery limit using the delivery-limit policy argument to drop messages that are redelivered multiple times.
If a message is redelivered more times than the delivery limit allows, the message is then dropped and deleted by RabbitMQ.
When you set a delivery limit, the message is requeued near the head of the queue.
Note
On RabbitMQ 4.2, quorum queues have a default delivery limit of 20. For more information, see Breaking changes in RabbitMQ 4.2 on Amazon MQ.
On RabbitMQ 4.3, you can update the quorum queue delivery limit using a policy without requiring queue redeclaration. For more information, see New features and enhancements in RabbitMQ 4.3 on Amazon MQ.
Message priority for quorum queues
Quorum queues on RabbitMQ 3.13 do not have message priority.
If you need message priority, use multiple quorum queues.
For more information, see Message priority
Note
On RabbitMQ 4.2, quorum queues use a 2:1 delivery ratio between high-priority (5 and higher) and normal-priority (0 through 4) messages. For more information, see New features and enhancements in RabbitMQ 4.2 on Amazon MQ.
On RabbitMQ 4.3, quorum queues support strict priority ordering with up to 32 levels, enabled by the x-max-priority queue argument.
For more information, see New features and enhancements in RabbitMQ 4.3 on Amazon MQ.
Using the default replication factor
Amazon MQ for RabbitMQ defaults to a replication factor of three (3) nodes for cluster brokers using quorum queues.
If you make changes to x-quorum-initial-group-size, Amazon MQ will default again to the replication
factor of 3.
