RabbitMQ & MQTT : how to alert a third party of non consumed messages?

Question

I am using RabbitMQ with the MQTT plugin, with both producer and consumer on QoS=1. I am still very new to RabbitMQ so I would like to understand if there is a way/efficient pattern to ensure a fallback in case a consumer is not consuming the messages of the topic he has subscribed to.

For instance, the idea being to be able to send an alert to a server trigger another channel (email, push notification) after a few seconds if a client is not consuming the messages of the MQTT topic?

Thank you for your help!

Answer 1

You can set per-message or per-queue TTL and then catch expired messages with the help of Dead Letter Exchanges extension. That will act as a notification of stalled or slow consumer or no consumers at all.