Setting up Oracle Event Hub (Apache Kafka) Cloud Service and Pub & Sub from local Node Kafka client image 38

Setting up Oracle Event Hub (Apache Kafka) Cloud Service and Pub & Sub from local Node Kafka client

Oracle offers an Event Bus Cloud Service – an enterprise grade Apache Kafka instance – with large numbers of partitions and topics, (retained) messages and distributed nodes. Setting up this cloud service is simple enough – especially once you know what to do, as I will demonstrate in this article. In order to communicate with this Event Bus from a local client – in this case created with Node – we need to open up some ports for access from the public internet.

The steps I went through:

  • create Oracle Event Hub Cloud Service – Platform instance (the Kafka & Zookeeper instance)
  • create Oracle Event Hub Cloud Service – Service instance (a Topic)
  • create two network rules to allow access from the public internet to ports 2181 – Zookeeper – and 6667 – Kafka Server)
  • create two Node applications using the kafka-node package – one to produce and one to consume (based on the work done by Kunal Rupani of Oracle (GitHub: https://github.com/kunalrupani/OracleEventHubConsumer)

Note: the Event Hub Cloud Service is a metered service, billed per hour. The cost for the smallest shape is around $0,70 per hour (or $200/month for non metered).

Create Oracle Event Hub Cloud Service – Platform instance (the Kafka & Zookeeper instance)

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Create Oracle Event Hub Cloud Service – Service instance (a Topic)

Switch to the Big Data Compute CS and select the service category Oracle Event Hub Cloud Service –Topics.

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Create two network rules to allow access from the public internet to ports 2181 – Zookeeper – and 6667 – Kafka Server)

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Create two Node applications using the kafka-node package

one to produce and one to consume (based on the work done by Kunal Rupani of Oracle (GitHub: https://github.com/kunalrupani/OracleEventHubConsumer)

Note: the topic was created as microEventBus. The actual name under which it is accessed is partnercloud17-microEventBus (which is identity domain as prefix to the topic name)

The package.json contains the dependency on kafka-node:

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The straightforward code for producing to the Event Hub Kafka Topic:

var EVENT_HUB_PUBLIC_IP = '129.xxxxxxxx';
var TOPIC_NAME = 'partnercloud17-microEventBus';
var ZOOKEEPER_PORT = 2181;

var kafka = require('kafka-node');
var Producer = kafka.Producer;
var client = new kafka.Client(EVENT_HUB_PUBLIC_IP + ':'+ZOOKEEPER_PORT);
var producer = new Producer(client);

let payloads = [
  { topic: TOPIC_NAME, messages: '*', partition: 0 }
];

console.log(payloads[0].messages);
setInterval(function () {
  console.log('called about every 1 second');
  producer.send(payloads, function (err, data) {
    if (err) {
      console.error(err);
    }
    console.log(data);
  });
  if (payloads[0].messages.length < 10) {
    payloads[0].messages = payloads[0].messages + "*";
  }
  else {
    payloads[0].messages = "*";
  }
}, 1000);

And the similar code for consuming. Note that the producer talks to Zookeeper (port 2181) and the consumer to the Kafka Server itself (port 6667):

var EVENT_HUB_PUBLIC_IP = '129xxxxxxx';
var TOPIC_NAME = 'partnercloud17-microEventBus';
var KAFKA_SERVER_PORT = 6667;

var kafka = require('kafka-node'),
    Consumer = kafka.Consumer,
    client = new kafka.KafkaClient({ "kafkaHost": EVENT_HUB_PUBLIC_IP + ':' + KAFKA_SERVER_PORT }),
    consumer = new Consumer(
        client,
        [
            { topic: TOPIC_NAME, offset: 1 }
        ],
        {
            autoCommit: false,
            fromOffset: true
        }
    );

consumer.on('message', function (message) {
    console.log(message.value)
});

Here is the output for producing:

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and here for consuming:

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