Why RPC enables request-reply over queues in RabbitMQ - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a queue named 'rpc_queue' in RabbitMQ.

RabbitMQ

channel.queue_declare(queue='[1]')

Drag options to blanks, or click blank then click option'

Arpc_queue

Btask_queue

Crequest_queue

Dreply_queue

Attempts:

3 left

💡 Hint

Common Mistakes

Using a queue name unrelated to RPC like 'task_queue'.

The queue named 'rpc_queue' is the standard name used for RPC requests in RabbitMQ examples.

2fill in blank

medium

Complete the code to send a message with a unique correlation_id for RPC.

RabbitMQ

channel.basic_publish(exchange='', routing_key='rpc_queue', properties=pika.BasicProperties(correlation_id='[1]'), body='Hello')

Drag options to blanks, or click blank then click option'

Areply_to

Bcorrelation_id

C12345

Dunique_id_1

Attempts:

3 left

💡 Hint

Common Mistakes

Using the literal string 'correlation_id' instead of a unique ID.

The correlation_id must be unique to match the reply with the request. 'unique_id_1' is an example of such an ID.

3fill in blank

hard

Fix the error in the code to consume replies from the reply queue using the correct queue name.

RabbitMQ

channel.basic_consume(queue='[1]', on_message_callback=on_response, auto_ack=True)

Drag options to blanks, or click blank then click option'

Arpc_queue

Breply_queue

Ctask_queue

Drequest_queue

Attempts:

3 left

💡 Hint

Common Mistakes

Using the request queue name instead of the reply queue.

The reply queue is where the client listens for responses. It is usually a temporary or named 'reply_queue'.

4fill in blank

hard

Fill both blanks to set the reply_to property and correlation_id in the RPC request message.

RabbitMQ

properties = pika.BasicProperties(reply_to='[1]', correlation_id='[2]')

Drag options to blanks, or click blank then click option'

Acallback_queue

Bunique_correlation_id

Crpc_queue

Dresponse_queue

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the reply_to queue name with the request queue name.

The 'reply_to' property tells the server where to send the response, usually a callback queue. The 'correlation_id' uniquely identifies the request.

5fill in blank

hard

Fill all three blanks to complete the RPC server callback function that sends a reply with the same correlation_id.

RabbitMQ

def on_request(ch, method, props, body):
    response = body.decode().upper()
    ch.basic_publish(exchange='', routing_key=props.[1], properties=pika.BasicProperties(correlation_id=props.[2]), body=response)
    ch.basic_ack(delivery_tag=method.[3])

Drag options to blanks, or click blank then click option'

Areply_to

Bcorrelation_id

Cdelivery_tag

Drouting_key

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong property names or missing message acknowledgment.

The server sends the reply to the queue specified in props.reply_to, uses the same correlation_id to match the request, and acknowledges the message with delivery_tag.