Scala Reactive Programming

Step2 – Implement PersistenceActor's receiveRecover

The next step is to provide an implementation for one of the important and mandatory functions (or methods) of PersistentActor trait—receiveRecover. It is defined with the following signature:

def receiveRecover: Receive

This function is also known as the recovery handler. It is used to restore the state of our Persistence Actor from its journal (such as MongoDB, Apache Cassandra, and so on) when an Actor is crashed, started, or restarted by its JVM or its Supervisor. This receiveRecover() function works in one the following two kinds of behaviors:

• Normal behavior (without the Snapshots feature): When this function is executed, it retrieves all available events related to that Persistence ...