How to Describe a Topic in Kafka: Syntax and Examples

To describe a topic in Kafka, use the kafka-topics.sh --describe --topic <topic-name> --bootstrap-server <broker-address> command. This shows details like partitions, replicas, and leader information for the specified topic.

Syntax

The command to describe a Kafka topic uses the kafka-topics.sh tool with these parts:

• --describe: tells Kafka to show topic details.
• --topic <topic-name>: specifies the topic you want to describe.
• --bootstrap-server <broker-address>: points to the Kafka broker to connect to.

bash

kafka-topics.sh --describe --topic <topic-name> --bootstrap-server <broker-address>

Example

This example shows how to describe a topic named my-topic on a Kafka broker running at localhost:9092. It lists partitions, leaders, replicas, and in-sync replicas.

bash

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

Output

Topic: my-topic	PartitionCount: 3	ReplicationFactor: 2	Configs: 
	Topic: my-topic	Partition: 0	Leader: 1	Replicas: 1,2	Isr: 1,2
	Topic: my-topic	Partition: 1	Leader: 2	Replicas: 2,1	Isr: 2,1
	Topic: my-topic	Partition: 2	Leader: 1	Replicas: 1,2	Isr: 1,2

Common Pitfalls

Common mistakes when describing Kafka topics include:

• Not specifying the --bootstrap-server option or using the wrong broker address, causing connection errors.
• Using --zookeeper option with newer Kafka versions (2.4+), which is deprecated.
• Misspelling the topic name or describing a topic that does not exist, resulting in no output or errors.

bash

Wrong (deprecated):
kafka-topics.sh --describe --topic my-topic --zookeeper localhost:2181

Right (modern):
kafka-topics.sh --describe --topic my-topic --bootstrap-server localhost:9092

Quick Reference

Remember these tips when describing Kafka topics:

• Always use --bootstrap-server with the broker address.
• Use exact topic names to avoid errors.
• Check Kafka version; avoid deprecated --zookeeper option.
• Output shows partitions, leaders, replicas, and in-sync replicas.

Key Takeaways

Use kafka-topics.sh --describe --topic <topic-name> --bootstrap-server <broker> to get topic details.

Avoid using the deprecated --zookeeper option in recent Kafka versions.

Ensure the broker address and topic name are correct to get valid output.

The output includes partition count, replication factor, leaders, replicas, and in-sync replicas.

Describing topics helps understand topic distribution and replication in Kafka.