Binding keys and routing keys in RabbitMQ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a direct exchange named 'logs'.

RabbitMQ

channel.exchange_declare(exchange='logs', exchange_type=[1])

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

Atopic

Bfanout

Cdirect

Dheaders

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'topic' or 'fanout' exchange types instead of 'direct'.

The direct exchange type routes messages with a routing key exactly matching the binding key.

2fill in blank

medium

Complete the code to bind queue 'error_logs' to exchange 'logs' with routing key 'error'.

RabbitMQ

channel.queue_bind(queue='error_logs', exchange='logs', routing_key=[1])

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

A'error'

B'debug'

C'warning'

D'info'

Attempts:

3 left

💡 Hint

Common Mistakes

Binding with wrong routing keys like 'info' or 'debug'.

The queue 'error_logs' should bind with routing key 'error' to receive error messages.

3fill in blank

hard

Fix the error in the code to publish a message with routing key 'info' to exchange 'logs'.

RabbitMQ

channel.basic_publish(exchange='logs', routing_key=[1], body='System started')

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

A'warning'

B'error'

C'start'

D'info'

Attempts:

3 left

💡 Hint

Common Mistakes

Using routing keys that do not match any binding key, causing message loss.

The routing key must be 'info' to route the message correctly to queues bound with that key.

4fill in blank

hard

Fill both blanks to declare a topic exchange named 'topic_logs' and bind queue 'critical_logs' with binding key 'kern.critical'.

RabbitMQ

channel.exchange_declare(exchange='topic_logs', exchange_type=[1])
channel.queue_bind(queue='critical_logs', exchange='topic_logs', routing_key=[2])

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

Atopic

Bdirect

C'kern.critical'

D'critical.kern'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'direct' exchange type for topic routing.

Swapping parts of the binding key incorrectly.

Use topic exchange type to enable pattern matching in routing keys. The binding key 'kern.critical' matches messages with that routing key.

5fill in blank

hard

Fill all three blanks to publish a message with routing key 'kern.info' to exchange 'topic_logs' and bind queue 'info_logs' with binding key 'kern.*'.

RabbitMQ

channel.basic_publish(exchange=[1], routing_key=[2], body='Kernel info message')
channel.queue_bind(queue='info_logs', exchange='topic_logs', routing_key=[3])

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

A'topic_logs'

B'kern.info'

C'kern.*'

D'info_logs'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong exchange name in publish.

Binding with incorrect pattern that won't match routing key.

Publish to 'topic_logs' exchange with routing key 'kern.info'. Bind queue with 'kern.*' to receive all messages starting with 'kern.' and one word after.

Practice

1. What is the main purpose of a binding key in RabbitMQ?

easy

A. To label messages for routing

B. To create a new exchange

C. To connect a queue to an exchange and filter messages

D. To delete a queue

Solution

1. Step 1: Understand the role of binding keys

   Binding keys link queues to exchanges and decide which messages the queue receives.

2. Step 2: Differentiate from routing keys

   Routing keys label messages, but binding keys filter messages for queues.

3. Final Answer:

   To connect a queue to an exchange and filter messages -> Option C

4. Quick Check:

   Binding key = filter for queues [OK]

Hint: Binding keys link queues to exchanges filtering messages [OK]

Common Mistakes:

• Confusing binding keys with routing keys
• Thinking binding keys create exchanges
• Assuming binding keys delete queues

2. Which of the following is the correct syntax to bind a queue named myQueue to an exchange myExchange with a binding key key.* using RabbitMQ CLI?

easy

A. rabbitmqadmin declare binding source=myExchange destination=myQueue routing_key=key.*

B. rabbitmqctl bind_queue myExchange myQueue key.*

C. rabbitmqctl declare binding myQueue myExchange key.*

D. rabbitmqadmin bind myQueue myExchange key.*

Solution

1. Step 1: Identify the correct RabbitMQ CLI command

   The rabbitmqadmin declare binding command is used to create bindings with source, destination, and routing_key parameters.

2. Step 2: Match parameters to syntax

   Source is the exchange, destination is the queue, and routing_key is the binding key pattern.

3. Final Answer:

   rabbitmqadmin declare binding source=myExchange destination=myQueue routing_key=key.* -> Option A

4. Quick Check:

   Use rabbitmqadmin declare binding with source, destination, routing_key [OK]

Hint: Use rabbitmqadmin declare binding with source, destination, routing_key [OK]

Common Mistakes:

• Using rabbitmqctl bind_queue which is not a valid command
• Swapping queue and exchange names
• Omitting routing_key parameter

3. Given a topic exchange with a queue bound using binding key logs.*.error, which routing key will deliver a message to this queue?

medium

A. logs.system.error

B. logs.error.system

C. logs.system.warning

D. error.logs.system

Solution

1. Step 1: Understand the binding key pattern

   The binding key logs.*.error matches routing keys with three words where the first is 'logs', the second can be any word, and the third is 'error'.

2. Step 2: Match each option to the pattern

   logs.system.error: 'logs.system.error' matches exactly.
   logs.error.system: 'logs.error.system' ends with 'system', not 'error'.
   logs.system.warning: 'logs.system.warning' ends with 'warning', not 'error'.
   error.logs.system: 'error.logs.system' does not start with 'logs'.

3. Final Answer:

   logs.system.error -> Option A

4. Quick Check:

   Binding key pattern matches routing key exactly [OK]

Hint: Match binding key wildcards to routing key words [OK]

Common Mistakes:

• Ignoring position of words in routing key
• Confusing '*' wildcard with '#' wildcard
• Assuming partial matches are enough

4. You have a queue bound to a topic exchange with binding key data.#. You send a message with routing key data but it is not received by the queue. What is the likely cause?

medium

A. Binding key data.# does not match routing key data

B. Routing key data should be data.#

C. Queue is not bound to the exchange

D. Binding key data.# matches routing key data, so the problem is elsewhere

Solution

1. Step 1: Check if binding key matches routing key

   The binding key data.# matches routing keys starting with 'data' and zero or more words after. The routing key 'data' matches because '#' can match zero words.

2. Step 2: Consider other causes

   Since the binding key matches, the message not arriving is likely due to other issues like queue not bound or exchange type mismatch.

3. Final Answer:

   Binding key data.# matches routing key data, so the problem is elsewhere -> Option D

4. Quick Check:

   Binding key '#' matches zero or more words [OK]

Hint: Remember '#' matches zero or more words including none [OK]

Common Mistakes:

• Thinking '#' requires at least one word
• Assuming routing key must equal binding key exactly
• Ignoring other configuration issues

5. You want to route messages with routing keys order.created and order.updated to a queue named orderQueue using a topic exchange. Which most specific binding key should you use to receive both types of messages?

hard

A. order.created, order.updated

B. order.*

C. *.created, *.updated

D. order.#

Solution

1. Step 1: Understand routing keys and binding keys

   Routing keys are 'order.created' and 'order.updated'. The binding key must match both.

2. Step 2: Analyze each binding key option

   order.*: 'order.*' matches 'order.created' and 'order.updated' because '*' matches exactly one word.
   order.#: 'order.#' matches these and more, but is broader than needed.
   *.created, *.updated: '*.created, *.updated' do not match because the first word must be 'order'.
   order.created, order.updated: 'order.created, order.updated' is not valid syntax for a single binding key; multiple bindings needed.

3. Final Answer:

   order.* -> Option B

4. Quick Check:

   'order.*' matches 'order.created' and 'order.updated' [OK]

Hint: Use 'order.*' to match one word after 'order' [OK]

Common Mistakes:

• Using '#' when '*' is enough
• Trying to use multiple keys in one binding key string
• Misplacing wildcards in binding keys