Implementing RPC client and server in RabbitMQ - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

RPC Server Response Behavior

Given a RabbitMQ RPC server that receives a request and replies with the square of the number sent, what will be the output on the client side if the client sends the number 5?

RabbitMQ

Client sends: 5
Server computes: 5 * 5
Server replies with the result

A 10

B 5

C 25

D Error: No response

💡 Hint

Think about what the server does with the number it receives.

The server squares the number 5, so the client receives 25 as the response.

❓ Configuration

intermediate

Correct Queue Declaration for RPC Server

Which queue declaration is correct for a RabbitMQ RPC server to receive requests and send replies properly?

A channel.queue_declare(queue='rpc_queue', durable=True, exclusive=True)

B channel.queue_declare(queue='rpc_queue')

C channel.queue_declare(queue='rpc_queue', auto_delete=True)

D channel.queue_declare(queue='rpc_queue', exclusive=True, auto_delete=True)

💡 Hint

The queue should be shared (not exclusive) for multiple clients.

The RPC server queue should be declared simply to receive requests; exclusive flags can interfere with multiple clients.

🔀 Workflow

advanced

Order of Steps in RPC Client Request

What is the correct order of steps a RabbitMQ RPC client follows to send a request and receive a response?

A 1,3,2,4

B 3,1,2,4

C 2,1,3,4

D 1,2,3,4

💡 Hint

Think about setting up the response channel before sending the request.

The client first declares the callback queue, then starts consuming from the callback queue, then sends the request with correlation ID and reply_to, and finally waits for the matching response.

❓ Troubleshoot

advanced

RPC Client Does Not Receive Response

A RabbitMQ RPC client sends a request but never receives a response. Which of the following is the most likely cause?

A The server did not send a reply with the correct correlation ID

B The client did not declare the request queue

C The client used a durable queue for the callback queue

D The server queue was declared as exclusive

💡 Hint

The client waits for a response with a matching correlation ID.

If the server replies without the correct correlation ID, the client will ignore the response and appear to never receive it.

✅ Best Practice

expert

Best Practice for Handling Multiple RPC Requests Concurrently

What is the best practice to handle multiple concurrent RPC requests efficiently in a RabbitMQ server?

A Set the RPC queue to auto-delete after each request

B Create a new queue for each client request

C Use a single-threaded server to process requests one by one

D Use multiple worker threads or processes consuming from the same RPC queue

💡 Hint

Think about scaling the server to handle many requests at once.

Using multiple workers consuming from the same queue allows parallel processing of RPC requests, improving throughput and responsiveness.