druid/docs/development/extensions-contrib/kafka-emitter.md

id	title
kafka-emitter	Kafka Emitter

To use this Apache Druid extension, include kafka-emitter in the extensions load list.

Introduction

This extension emits Druid metrics to Apache Kafka directly with JSON format.
Currently, Kafka has not only their nice ecosystem but also consumer API readily available. So, If you currently use Kafka, It's easy to integrate various tool or UI to monitor the status of your Druid cluster with this extension.

Configuration

All the configuration parameters for the Kafka emitter are under druid.emitter.kafka.

Property	Description	Required	Default
druid.emitter.kafka.bootstrap.servers	Comma-separated Kafka broker. ([hostname:port],[hostname:port]...)	yes	none
druid.emitter.kafka.event.types	Comma-separated event types. Supported types are alerts, metrics, requests, and segment_metadata.	no	["metrics", "alerts"]
druid.emitter.kafka.metric.topic	Kafka topic name for emitter's target to emit service metrics. If event.types contains metrics, this field cannot be empty.	no	none
druid.emitter.kafka.alert.topic	Kafka topic name for emitter's target to emit alerts. If event.types contains alerts, this field cannot empty.	no	none
druid.emitter.kafka.request.topic	Kafka topic name for emitter's target to emit request logs. If event.types contains requests, this field cannot be empty.	no	none
druid.emitter.kafka.segmentMetadata.topic	Kafka topic name for emitter's target to emit segment metadata. If event.types contains segment_metadata, this field cannot be empty.	no	none
druid.emitter.kafka.producer.config	JSON configuration to set additional properties to Kafka producer.	no	none
druid.emitter.kafka.clusterName	Optional value to specify the name of your Druid cluster. It can help make groups in your monitoring environment.	no	none
druid.emitter.kafka.extra.dimensions	Optional JSON configuration to specify a map of extra string dimensions for the events emitted. These can help make groups in your monitoring environment.	no	none

Example

druid.emitter.kafka.bootstrap.servers=hostname1:9092,hostname2:9092
druid.emitter.kafka.event.types=["metrics", alerts", "requests", "segment_metadata"]
druid.emitter.kafka.metric.topic=druid-metric
druid.emitter.kafka.alert.topic=druid-alert
druid.emitter.kafka.request.topic=druid-request-logs
druid.emitter.kafka.segmentMetadata.topic=druid-segment-metadata 
druid.emitter.kafka.producer.config={"max.block.ms":10000}
druid.emitter.kafka.extra.dimensions={"region":"us-east-1","environment":"preProd"}