Learning Akka (Video 22)

The video tutorial introduces the concept of a cluster Singleton, explaining its purpose and use cases, such as ensuring a single point of responsibility in a cluster. It discusses the implementation details, including the role of the cluster Singleton manager and proxy. The tutorial also covers the master actor's commands and events, the worker actor's role, and the overall logic for communication within the cluster. Finally, it demonstrates the app implementation, highlighting the setup of nodes and the execution of tasks within the cluster.

What is one of the main purposes of using a Cluster Singleton?

• To ensure multiple actors of the same type run simultaneously

• To provide a single point of responsibility for cluster-wide decisions

• To increase the number of nodes in a cluster

• To eliminate the need for load balancing

Which of the following is a drawback of using a Cluster Singleton?

• It ensures nonstop availability

• It allows for multiple entry points to external systems

• It can become a performance bottleneck

• It simplifies the cluster configuration

What role does the Cluster Singleton Manager play?

• It disables the Singleton actor when not needed

• It manages multiple instances of the Singleton actor

• It manages one instance of the Singleton actor across nodes

• It duplicates the Singleton actor on all nodes

How does the Cluster Singleton Proxy function?

• It creates new Singleton actors

• It routes messages to the current Singleton instance

• It deletes old Singleton actors

• It manages the cluster's load balancing

What happens when the master actor receives a 'register worker' command?

• It persists the 'add worker' event

• It sends a 'no work' reply

• It deletes the worker

• It ignores the command

What is the purpose of scheduling tasks every 30 seconds in the application?

• To restart the Singleton actor

• To update the cluster configuration

• To delete old log entries

• To send the 'register worker' message

What is a potential risk of using a single Journal in production?

• It becomes a single point of failure

• It simplifies the cluster setup

• It can lead to data duplication

• It increases the number of nodes