Kafka CLI Quick Reference

Create topics, produce and consume messages, and inspect consumer-group lag from the command line.

Topics

Create
kafka-topics.sh --create --topic orders --partitions 6 --replication-factor 3 --bootstrap-server localhost:9092
List / describe
kafka-topics.sh --list … · --describe --topic orders …
Add partitions
kafka-topics.sh --alter --topic orders --partitions 12 … (can’t shrink)
Delete
kafka-topics.sh --delete --topic orders …

Produce & consume

Produce (stdin)
kafka-console-producer.sh --topic orders --bootstrap-server …
Produce with key
add --property parse.key=true --property key.separator=:
Consume from start
kafka-console-consumer.sh --topic orders --from-beginning …
Consume in a group
add --group my-group — offsets are committed
Show keys
add --property print.key=true

Consumer groups (lag)

List groups
kafka-consumer-groups.sh --list --bootstrap-server …
Describe (lag!)
kafka-consumer-groups.sh --describe --group my-group … — CURRENT-OFFSET, LOG-END-OFFSET, LAG
Reset offsets
--reset-offsets --to-earliest --topic orders --execute --group my-group