Kafka Consumer for Fluentd
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Kafka Consumer for Fluentd

This integration is a simple Java application that you can use to consume data from Kafka to Fluentd. You can download the application from this page and then complete the following instructions.


Use gradle 2.1 or later.

$ gradle shadowJar


Run Kafka

You need to be running Kafka for the consumer to work. To test Kafka locally, follow the steps described in Kafka's Quickstart.

# start zookeeper
$ bin/zookeeper-server-start.sh config/zookeeper.properties

# start kafka
$ bin/kafka-server-start.sh config/server.properties

Then create a topic called test

# create test topic
$ bin/kafka-topics.sh --create --zookeeper localhost:2181 --replication-factor 1 --partitions 1 --topic test

When the 'test' topic is created, add a few messages in it. Make sure message is valid JSON.

# send multiple messages
$ bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test 
{"a": 1}
{"a": 1, "b": 2}

You can confirm messages were submitted correctly with this command.

$ bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic test --from-beginning
{"a": 1}
{"a": 1, "b": 2}

Run Kafka Consumer for Fluentd

Modify config/fluentd-consumer.properties with an appropriate configuration. Remember to change to fluentd.consumer.topics=test. Then, launch the process like this.

$ java -Dlog4j.configuration=file:///path/to/log4j.properties -jar build/libs/kafka-fluentd-consumer-0.3.2-all.jar config/fluentd-consumer.properties

This will forward logs to Fluentd (localhost:24224). This consumer uses log4j so you can change logging configurations via -Dlog4j.configuration argument.

Run Kafka Consumer for Fluentd via in_exec

To host a consumer as a child process of Fluentd, use the following code:

  type forward

  type exec
  command java -Dlog4j.configuration=file:///path/to/log4j.properties -jar /path/to/kafka-fluentd-consumer-0.3.2-all.jar /path/to/config/fluentd-consumer.properties
  tag dummy
  format json

Enterprise Fluentd

Treasure Data offers Enterprise Fluentd for those looking for enterprise certified connectors for Kafka among other enterprise features (packaging, security, monitoring and support).


  • Support more format, e.g. msgpack.
  • Add metrics features