Resend lost messages after akka actor restarted


I have a program with 2 actors: parent actor A and child actor B.
Actor A sends messages to actor B.
When actor B is failing, all messages that actor A sends are lost, and my aim is to re-send these lost messages when actor B is restarted.
How can I implement that?maybe using acknowledgment per message?if so , how?

It’s right that you need to acknoledge the messages and resend missing. You might find the AtLeastOnceDelivery utility useful.