How to change Kafka attribute of a dead letter queue

[MarcG]

Hi,

I need to change the default Kafka max.request.size for a dead letter queue using the application configuration.

This dead letter queue is defined in the following way:
mp.messaging.incoming.my-topic-in.failure-strategy=dead-letter-queue
mp.messaging.incoming.my-topic-in.dead-letter-queue.topic=my.topic.deadLetter

I tried to set this attribute using the following properties:
mp.messaging.outgoing.my-topic-deadLetter-out.topic=sws.detection.new.deadLetter
mp.messaging.outgoing.my-topic-deadLetter-out.max.request.size=10485880
mp.messaging.outgoing.my-topic-deadLetter-out.connector=smallrye-kafka

But as there is no upstream producer defined in the application, I've the following WARN:
WARN  [io.sma.rea.mes.provider] (Quarkus Main Thread) SRMSG00207...

Do I have to define a dummy procuder for this dead letter topic ? Or is there a different way to define such attribute using the application configuration ?

Thank you!
Marc