Direct exchange in RabbitMQ - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

How does a direct exchange route messages in RabbitMQ?

In RabbitMQ, a direct exchange routes messages based on which of the following?

A The message header contains a matching key-value pair

B The exchange randomly selects a queue to send the message

C The message is broadcast to all queues regardless of keys

D The routing key exactly matches the binding key of the queue

💡 Hint

Think about how direct exchanges use routing keys to deliver messages.

A direct exchange delivers messages to queues where the routing key exactly matches the queue's binding key. This allows precise routing.

💻 Command Output

intermediate

What is the output of binding a queue with a routing key?

Given the RabbitMQ command below, what is the expected result?

rabbitmqadmin declare binding source=direct_logs destination=my_queue routing_key=error

A The queue 'my_queue' will receive all messages from 'direct_logs' exchange regardless of routing key

B The queue 'my_queue' will receive messages sent to 'direct_logs' exchange with routing key 'error'

C The command will fail because 'routing_key' is not valid in binding declaration

D The queue 'my_queue' will receive messages only if the exchange type is 'fanout'

💡 Hint

Consider what binding with a routing key does in a direct exchange.

Binding a queue with a routing key means the queue receives messages from the exchange only if the message's routing key matches the binding key.

🔀 Workflow

advanced

Order the steps to set up a direct exchange with a queue and binding

Arrange the following steps in the correct order to set up a direct exchange named 'logs', a queue named 'error_logs', and bind them with routing key 'error'.

A 1,3,2,4

B 2,1,3,4

C 1,2,3,4

D 3,1,2,4

💡 Hint

Think about what must exist before binding and publishing.

You must first declare the exchange, then the queue, then bind them before publishing messages.

❓ Troubleshoot

advanced

Why does a queue not receive messages from a direct exchange?

You have a direct exchange 'logs' and a queue 'info_logs' bound with routing key 'info'. You publish a message with routing key 'warning' but 'info_logs' does not receive it. Why?

A Because the routing key 'warning' does not match the binding key 'info'

B Because the queue 'info_logs' is not declared

C Because the message was published to the wrong exchange type

D Because direct exchanges broadcast messages to all queues regardless of routing key

💡 Hint

Recall how direct exchanges route messages based on routing keys.

Direct exchanges deliver messages only to queues with matching binding keys. Since 'warning' ≠ 'info', the queue does not get the message.

✅ Best Practice

expert

Which practice ensures reliable message delivery with direct exchanges?

When using a direct exchange in RabbitMQ, which practice best ensures that messages are not lost if the consumer is temporarily offline?

A Declare the queue as durable and publish messages as persistent

B Use a non-durable queue and transient messages for faster delivery

C Bind multiple queues with different routing keys to the exchange

D Publish messages without specifying a routing key to reach all queues

💡 Hint

Think about how RabbitMQ handles message durability and persistence.

Declaring queues as durable and publishing persistent messages ensures messages survive broker restarts and are stored until consumed.