Learning Akka (Video 15)

This video tutorial explains how to implement a persistent actor in a system. It covers defining operations, commands, and events, and how to handle recovery and command reception. The tutorial also demonstrates testing the app to ensure it starts with the previous state, highlighting the persistence feature. The video concludes with a preview of the next tutorial, which will focus on snapshots and recovery.

What are the two types of messages that a persistent actor handles?

• Commands and Responses

• Commands and Events

• Requests and Responses

• Signals and Slots

What must be unique for each persistent actor?

• Command Type

• State Variable

• Persistence ID

• Actor Name

Which function is responsible for handling the recovery state of a persistent actor?

• updateState

• persistenceID

• receiveCommand

• receiveRecover

What does the persist method require as arguments?

• State and Command

• Event and State

• Command and Handler

• Event and Handler

What happens when the application is restarted with a persistent actor?

• The actor loses all its data

• The actor resets its persistence ID

• The actor starts from the previous state

• The actor starts from a clean state