Petals CDK

It means that from the point of view of the sender/consumer – the one who did the sendAsync and the one for whom the concept of expiration means something --, once the expiration occurred, it makes no sense for the component to send back this exchange (e.g., when an error occurred, or by default by returning true with the method onExpiredAsyncJBIMessage).

Of course it has no meaning from the point of view of the provider, I thought it was obvious, since he doesn't know anything about asynchronous sending.

I don't understand what you mean by this issue. Can you add explanations ?

IMO: when the timeout of a sendAsync expires, the exchange is terminated in a point of view of the service consumer, but the exchange is always in progress in the point of view of the service provider because it was not informed that the timeout expired.