Event sourcing with RabbitMQ - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Event Sourcing with RabbitMQ

What is the primary role of RabbitMQ in an event sourcing architecture?

A To store the complete state of the application in a database

B To act as a message broker that transports events between services

C To execute business logic when events occur

D To replace the need for event storage entirely

💡 Hint

Think about what RabbitMQ does best in a system that uses events.

RabbitMQ is a message broker that transports events reliably between producers and consumers. It does not store the full application state or execute business logic.

💻 Command Output

intermediate

RabbitMQ Queue Declaration Output

What is the output of the following RabbitMQ CLI command?

rabbitmqctl list_queues

A Empty output with no queues listed

B Error: RabbitMQ server not running

C Syntax error: command not found

D Listing of all queues with their message counts

💡 Hint

This command lists queues and their message counts if the server is running.

The rabbitmqctl list_queues command outputs all queues with their message counts if RabbitMQ is running properly.

❓ Configuration

advanced

Configuring a Durable Queue for Event Sourcing

Which RabbitMQ queue configuration ensures that events are not lost if the broker restarts?

A queue_declare(queue='events', durable=False)

B queue_declare(queue='events', exclusive=True)

C queue_declare(queue='events', durable=True)

D queue_declare(queue='events', auto_delete=True)

💡 Hint

Durability means the queue survives broker restarts.

Setting durable=True makes the queue survive RabbitMQ restarts, which is critical for event sourcing to avoid losing events.

🔀 Workflow

advanced

Event Publishing and Consumption Workflow

In an event sourcing system using RabbitMQ, what is the correct order of steps when a new event is generated?

A 2,1,3,4

B 1,3,4,2

C 1,2,3,4

D 2,3,1,4

💡 Hint

Think about storing the event before publishing it.

In event sourcing, the event is first stored in the event store, then published to RabbitMQ exchange, routed to queues, and finally consumed.

❓ Troubleshoot

expert

Diagnosing Missing Events in RabbitMQ

You notice that some events are missing from your consumer application logs. Which RabbitMQ misconfiguration is the most likely cause?

A The queue is declared as non-durable and RabbitMQ was restarted.

B The exchange type is set to 'fanout'.

C The consumer is using manual acknowledgments.

D The queue has a high prefetch count.

💡 Hint

Consider what happens to non-durable queues on broker restart.

Non-durable queues are deleted when RabbitMQ restarts, causing events to be lost and missing from consumers.