So if I understand your solution with an external Kafka/RabbitMQ, Graylog will trigger a job when it sees a message in the queue, process the work to do, and only then clear the message in the queue.
This is what would be optimal for me/us.
However, I am wondering where I can notify Graylog that I want to use an extrenal message broker, I can’t find it in the doc.
Moreover, I think it could be a good thing that you have a vision of the overall project, that is to un Graylog on top of Kubernetes, with HA and no loss of data/work. That is whhy we are looing for a way to make Graylog stateless.