Contents

• Produce
• Consume
• List Topics
• Read Messages From File
• Generate a Test File of Messages
• Read the Last n Messages from Partition n

kafkacat is a useful tool for working with Kafka brokers. It’s quick and very simple to use. This is a cheatsheet of some useful commands.

Produce

$ echo "foo" | kafkacat -b localhost:9092 -t mytopic

Consume

kafkacat -C -b localhost:9092  -t mytopic

List Topics

kafkacat  -b localhost:9092 -L -t mytopic

Read Messages From File

Read messages from a file, with each message separated by a newline:

kafkacat -P -l -b kafka:9092 -t mytopic myfile

Generate a Test File of Messages

Given a file containing a DATE variable, generate a set of messages with incrementing timestamp, for use with the previous example:

for i in {1..5000}; do DATE=`date -u +%d/%b/%Y:%H:%M:%S`; sed "s~DATE~$DATE~" template.msg >> myfile; done

Read the Last n Messages from Partition n

This example uses the -o flag to read from a specified offset. Specifying -3 allows retrieval of the last 3 messages. The -p option targets partition 0:

kafkacat -C -b kafka -t mytopic -o -3 -e -p 0