We have an Azure Function app binding setup with Service bus, so that it is triggered when a message goes onto a Queue. However imagine if we disable the Function app, or it is down for whatever reason and some messages backlog onto the Service bus Queue.
How do we then re-trigger the Function app for existing messages? It only appears to pickup new messages. I can't see it just picking existing ones off. Is there a way to make it retrigger itself for existing messages?