Working with Send the message to brokers

Overview

The following operations allow you to work with the messages. Click an operation name to see details on how to use it.

For a sample proxy service that illustrates how to work with sending the messages to brokers, see Sample configuration.

Operation details

This section provides details on the operations.

Publishing the messages to the Kafka brokers

The kafkaproduce-operation operation sends the messages to brokers using the topic

<kafkaTransport.kafkaproduce-operation>
	<topic>{$ctx:topic}</topic>
</kafkaTransport.kafkaproduce-operation>

Sample configuration

• Download and install Apache Kafka. For more information, see Apache Kafka documentation. 

• Copy the following client libraries from the <KAFKA_HOME>/lib directory to the <ESB_HOME>/repository/components/lib directory.

  • kafka_2.9.2-0.8.1.1.jar
  • scala-library-2.9.2.jar
  • zkclient-0.3.jar
  • zookeeper-3.3.4.jar
  • metrics-core-2.2.0.jar

• Run the following command to start the ZooKeeper server:

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

  You will see the following log:
  

• Run the following command to start the Kafka server
  bin/kafka-server-start.sh config/server.properties
  You will see the following log:
  
  
  
• Following is a sample proxy service that illustrates how to connect to Kakfa brokers with the init operation and use the kafkaproduce-operation operation to send the messages with the topic.
  
  

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="KafkaTransport"
       transports="https http"
       startOnLoad="true"
       trace="disable">
   <description/>
   <target>
      <inSequence>
         <kafkaTransport.init>
            <brokerList>localhost:9092</brokerList>
         </kafkaTransport.init>
         <kafkaTransport.kafkaproduce-operation>
            <topic>test</topic>
         </kafkaTransport.kafkaproduce-operation>
      </inSequence>
   </target>
</proxy>            

The following image shows how to send the messages using a sample client(JMeter).

Analyzing the output

• Run the following command to verify the messages
  

  bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic test --from-beginning

     You will see the following Message content:

          <name>sample</name>

         The Kafka connector publishes the messages from the Kafka brokers.