Chapter 23. Configuring a service and KIE Server to send Kafka messages when a transaction is committed

Procedure

1. To send Kafka messages automatically, complete one of the following tasks:

   1. If you deployed KIE Server on Red Hat JBoss EAP or another application server, complete the following steps:

      1. Download the rhpam-7.13.5-maven-repository.zip product deliverable file from the Software Downloads page of the Red Hat Customer Portal.
      2. Extract the contents of the file.
      3. Copy the maven-repository/org/jbpm/jbpm-event-emitters-kafka/7.67.0.Final-redhat-00024/jbpm-event-emitters-kafka-7.67.0.Final-redhat-00024.jar file into the deployments/kie-server.war/WEB-INF/lib subdirectory of the application server.

   2. If you deployed the application using SpringBoot, add the following lines to the <dependencies> list in the pom.xml file of your service:

      <dependency>
        <groupId>org.jbpm</groupId>
        <artifactId>jbpm-event-emitters-kafka</artifactId>
        <version>${version.org.kie}</version>
      </dependency>

2. Configure any of the following KIE Server system properties as necessary:

   Table 23.1. KIE Server system properties related to the Kafka emitter

   Property	Description	Default value
   org.kie.jbpm.event.emitters.kafka.bootstrap.servers:	The host and port of the Kafka broker. You can use a comma-separated list of multiple host:port pairs.	localhost:9092
   org.kie.jbpm.event.emitters.kafka.date_format:	The timestamp format for the time field of the messages.	yyyy-MM-dd’T’HH:mm:ss.SSSZ
   org.kie.jbpm.event.emitters.kafka.topic.processes	The topic name for process event messages.	jbpm-processes-events
   org.kie.jbpm.event.emitters.kafka.topic.cases	The topic name for case event messages.	jbpm-cases-events
   org.kie.jbpm.event.emitters.kafka.topic.tasks	The topic name for task event messages.	jbpm-processes-tasks
   org.kie.jbpm.event.emitters.kafka.client.id	An identifier string to pass to the server when making requests. The server uses this string for logging.
   org.kie.jbpm.event.emitters.kafka.property_name	Set any Red Hat AMQ Streams consumer or producer property by using this prefix. For example, to set a value for the buffer.memory producer property, set the org.kie.jbpm.event.emitters.kafka.buffer.memory KIE Server system property. This setting applies when KIE Server is configured with an emitter to send Kafka messages automatically when completing transactions. For a list of Red Hat AMQ Streams consumer and producer properties, see the Consumer configuration parameters and Producer configuration parameters appendixes in Using AMQ Streams on RHEL.
   org.kie.jbpm.event.emitters.eagerInit	By default, KIE Server initializes the Kafka emitter only when sending a message. If you want to initialize the Kafka emitter when KIE Server starts, set this property to true. When KIE Server initializes the Kafka emitter, it logs any errors in Kafka emitter configuration and any Kafka communication errors. If you set the org.kie.jbpm.event.emitters.eagerInit property to true, any such errors appear in the log output when KIE Server starts.	false