Topic deletion and cleanup in Kafka - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of the Kafka topic deletion command?

Given the command to delete a Kafka topic, what will be the output if the topic exists and deletion is successful?

Kafka

kafka-topics.sh --delete --topic my-topic --bootstrap-server localhost:9092

A Topic 'my-topic' marked for deletion.

B Error: Topic 'my-topic' does not exist.

C Topic 'my-topic' deleted immediately.

D Warning: Topic deletion is disabled.

💡 Hint

Think about how Kafka handles topic deletion asynchronously.

Kafka marks the topic for deletion but the actual removal happens asynchronously. The command outputs a confirmation that the topic is marked for deletion.

🧠 Conceptual

intermediate

What happens if topic deletion is disabled in Kafka?

If the Kafka broker configuration has 'delete.topic.enable=false', what will happen when you try to delete a topic?

A The topic will remain and no deletion occurs.

B The topic will be marked for deletion but not removed.

C The deletion command will fail with an error.

D The topic will be deleted immediately.

💡 Hint

Consider the effect of disabling topic deletion in Kafka broker settings.

When 'delete.topic.enable' is false, Kafka ignores delete requests and the topic remains intact without any deletion.

🔧 Debug

advanced

Why does the topic not get deleted after issuing the delete command?

You ran the command to delete a Kafka topic, but the topic still appears in the list. What could be the reason?

Kafka

kafka-topics.sh --delete --topic test-topic --bootstrap-server localhost:9092
kafka-topics.sh --list --bootstrap-server localhost:9092

A The topic is marked for deletion but the broker has not completed cleanup yet.

B The topic name was misspelled in the delete command.

C The topic has active consumers preventing deletion.

D The Kafka broker has 'delete.topic.enable' set to false.

💡 Hint

Check the broker configuration related to topic deletion.

If 'delete.topic.enable' is false, Kafka will not delete topics even if the delete command is issued, so the topic remains listed.

📝 Syntax

advanced

Which command correctly deletes a Kafka topic named 'orders'?

Choose the correct syntax to delete the Kafka topic 'orders' using kafka-topics.sh with bootstrap server localhost:9092.

A kafka-topics.sh --remove --topic orders --bootstrap-server localhost:9092

B kafka-topics.sh --delete --topic orders --bootstrap-server localhost:9092

C kafka-topics.sh --delete-topic orders --server localhost:9092

D kafka-topics.sh --delete orders --bootstrap-server localhost:9092

💡 Hint

Check the official kafka-topics.sh command syntax for deleting topics.

The correct syntax uses '--delete' and '--topic' flags with '--bootstrap-server' to specify the broker.

🚀 Application

expert

How to ensure complete cleanup of deleted Kafka topics?

After deleting a Kafka topic, which steps ensure that all data and metadata related to the topic are fully cleaned up from the Kafka cluster?

A Run kafka-topics.sh with --force-delete flag to remove topic instantly.

B Restart all Kafka brokers immediately after issuing the delete command.

C Wait for Kafka to asynchronously delete topic data, then manually delete topic directories from brokers if needed.

D Delete the topic and then run kafka-configs.sh to remove topic configs.

💡 Hint

Think about Kafka's asynchronous deletion and broker storage cleanup.

Kafka deletes topic data asynchronously. Sometimes manual cleanup of topic directories on brokers is needed if deletion is stuck or incomplete.