Distributed Systems and Cloud Computing: The Actor Model

What is the term used to describe actors that create other actors?

Supervisors (correct)
Workers
Nodes
Sentinels

How many common recovery steps are there when a worker hits a problem?

4 (correct)
3
2
5

What type of actors watch actors on other nodes in the cluster?

Worker actors
Sentinel actors (correct)
Supervisor actors
Node actors

What is a major reason for the need to run code concurrently?

Multiple cores are available on modern CPUs (A) Signup and view all the answers

What is the name of the manifesto that Akka adheres to?

The Reactive Manifesto (C) Signup and view all the answers

What is one of the requirements of reactive applications?

Being event-driven (D) Signup and view all the answers

What is a characteristic of messages in the Actor Model?

They are immutable (B) Signup and view all the answers

What does Akka create a layer between?

Actors and the underlying system (D) Signup and view all the answers

What is the purpose of an actor's mailbox?

To buffer messages from other actors (A) Signup and view all the answers

What is the role of the Dispatcher in the Actor Model?

To ensure actors with nonempty mailboxes eventually get run by a specific thread (B) Signup and view all the answers

What can an actor do according to the Actor Model?

Create more actors and send messages to other actors (C) Signup and view all the answers

What happens to the workload when an office is larger?

It can handle more work. (A) Signup and view all the answers

How does an actor process messages from other actors?

Sequentially, one at a time (D) Signup and view all the answers

What is sent to the office and then routed to each worker?

Messages (D) Signup and view all the answers

What happens when messages arrive faster than the workers can perform each task?

There is a backlog of pending messages. (A) Signup and view all the answers

When do workers occupy desks in an asynchronous system?

When they have something to do. (B) Signup and view all the answers

What feature is available in actor systems that run in a cluster?

Failure detection and recovery. (B) Signup and view all the answers

What is the primary function of an actor's createReceive() method?

To identify the message type and react accordingly (C) Signup and view all the answers

What is an ActorSystem in Akka?

A hierarchical group of actors sharing common configuration (A) Signup and view all the answers

What can an actor do upon receiving a message?

Execute some operations itself, forward the message, or instantiate a new actor (D) Signup and view all the answers

What is the purpose of the matchAny() method?

To catch any unmatched message (B) Signup and view all the answers

What is the entry point for creating or looking up actors in Akka?

The ActorSystem class (A) Signup and view all the answers

What is the parent class of an actor implementation in Akka?

AbstractActor (D) Signup and view all the answers

What is the purpose of the Props class in Akka?

To create actors (B) Signup and view all the answers

How can you create a child actor in Akka?

Using the implicit context reference (C) Signup and view all the answers

What are the two predefined methods provided by Akka for message exchange?

tell() and ask() (C) Signup and view all the answers

What is the purpose of the preStart() method in Akka's actor life cycle?

To initialize the actor before it starts (D) Signup and view all the answers

How do actors communicate with each other in Akka?

By sending and receiving messages (C) Signup and view all the answers

What is the purpose of the ActorSystem in Akka?

To create a root-level or top-level actor (C) Signup and view all the answers