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?
You do not need to re trigger the function, if your received becomes unavailable the messages will stay in the queue until a working receiver picks them up.
What makes you think its not behaving like this?
Could it be that you have multiple receivers?