Kyuubi provide event processing mechanism, it can help us to record some events. Beside the builtin JsonLoggingEventHandler, Kyuubi supports custom event handler. It is usually used to write Kyuubi events to some external systems. For example, Kafka, ElasticSearch, etc. The org.apache.kyuubi.events.handler.CustomEventHandlerProvider has a zero-arg constructor, it can help us to create a custom EventHandler.

package org.apache.kyuubi.events.handler
import org.apache.kyuubi.config.KyuubiConf
import org.apache.kyuubi.events.KyuubiEvent
/**
 * Custom EventHandler provider. We can implement it to provide a custom EventHandler.
 * The implementation will be loaded by ``Service Provider Interface``.
 */
trait CustomEventHandlerProvider {
  /**
   * The create method is called to create a custom event handler
   * when this implementation is loaded.
   *
   * @param kyuubiConf The conf can be used to read some configs.
   * @return A custom handler to handle KyuubiEvent.
   */
   def create(kyuubiConf: KyuubiConf): EventHandler[KyuubiEvent]
}

Build A Custom EventHandler

To create custom EventHandlerProvider class derived from the above interface, we need to:

• Referencing the library

<dependency>
    <groupId>org.apache.kyuubi</groupId>
    <artifactId>kyuubi-events_2.12</artifactId>
    <version>1.9.1</version>
    <scope>provided</scope>
</dependency>

• Implement org.apache.kyuubi.events.handler.CustomEventHandlerProvider
• Adding a file named org.apache.kyuubi.events.handler.CustomEventHandlerProvider in the src/main/resources/META-INF/services folder of project, its content is the custom class name.

Enable Custom EventHandler

To enable the custom EventHandler, we need to

• Put the jar package to $KYUUBI_HOME/jars directory to make it visible for the classpath of the kyuubi server.
• Configure the following properties to $KYUUBI_HOME/conf/kyuubi-defaults.conf on each node where kyuubi server is installed. If you need use other event handler, it can be appended after the CUSTOM.

kyuubi.backend.server.event.loggers=CUSTOM

• Restart all the kyuubi server instances.