This lecture treats the most important characteristic of Actors, namely how they support handling failures in a principled fashion. Due to their encapsulation, failure is contained within the compartment of the system that is represented by each Actor. We therefore cover:
how failure is communicated to a supervisor Actor in order to react to it
how the supervisor decides its reaction
helpful utilities offered by Akka for formulating supervision strategies
how the various reactions (resume/restart/stop) affect the failed Actor
how a restarted Actor can react to this event
We summarize these learnings by drawing a diagram of the Actor lifecycle.