Back-End Development Message Queues and Event-Driven Architecture 2

Question 1

How does Apache Kafka differ from traditional message queues?

Accepted Answer

It stores messages as an immutable, ordered log that consumers can replay

Answer

It only supports JSON-formatted messages

Answer

It requires all consumers to process messages synchronously

Answer

It uses HTTP instead of TCP for message transport

Question 2

In RabbitMQ, what is the role of an 'exchange'?

Accepted Answer

A routing component that receives messages and routes them to queues based on rules

Answer

A persistent storage layer for undelivered messages

Answer

A consumer group that load-balances incoming messages

Answer

A protocol adapter between AMQP and HTTP

Question 3

What is a Kafka consumer group?

Accepted Answer

A collection of consumers that together consume all partitions of a topic

Answer

A set of producers writing to the same topic

Answer

A cluster of Kafka brokers sharing storage

Answer

An admin group for managing Kafka topic configurations

Question 4

What does 'at-least-once delivery' mean in a messaging system?

Accepted Answer

A message is delivered one or more times, potentially resulting in duplicates

Answer

A message is delivered exactly one time to exactly one consumer

Answer

A message is delivered only if the consumer is currently online

Answer

A message is delivered to at least half of all registered consumers

Question 5

What is 'event sourcing' in back-end architecture?

Accepted Answer

Storing all state changes as an ordered, immutable sequence of events

Answer

Logging only the final state of an entity after each change

Answer

Generating synthetic test events for load and performance testing

Answer

Pulling events from external third-party APIs into an internal system

Question 6

In Apache Kafka, what is a 'partition'?

Accepted Answer

An ordered, immutable sequence of messages within a topic

Answer

A logical grouping of brokers for high availability

Answer

A consumer group boundary that isolates message processing

Answer

A dedicated disk volume used for message persistence

Question 7

What routing behavior does RabbitMQ's 'direct exchange' provide?

Accepted Answer

It routes messages to queues whose binding key exactly matches the message routing key

Answer

It delivers messages to all bound queues simultaneously

Answer

It uses message header attributes to make routing decisions

Answer

It distributes messages evenly across all available queues in round-robin