Integrating Apache Beam with Apache Kafka Connect using Java

25 Sep 2023

In this blog post, we will explore how to integrate Apache Beam, a unified programming model for both batch and streaming data processing, with Apache Kafka Connect, a scalable and fault-tolerant framework for connecting Kafka with external systems. We will be using the Java programming language for this integration.

Prerequisites

Before we delve into the integration process, make sure you have the following prerequisites in place:

Apache Kafka and Apache Kafka Connect installed and running.
Apache Beam SDK for Java.
Java Development Kit (JDK) installed on your machine.

Step 1: Setting up Apache Kafka Connect

The first step is to set up the Apache Kafka Connect framework. Follow the official documentation to install and configure Kafka Connect properly. We will be using Kafka Connect in standalone mode for simplicity.

Step 2: Creating a Kafka Source Connector

To integrate Apache Beam with Kafka Connect, we need to create a Kafka Source Connector. This connector will be responsible for consuming data from a Kafka topic and sending it to Apache Beam for further processing.

Create a JSON configuration file (e.g., kafka-source-connector.json) with the following content:

{
  "name": "beam-kafka-source-connector",
  "config": {
    "connector.class": "io.confluent.connect.kafka.KafkaSourceConnector",
    "tasks.max": "1",
    "topic": "your-kafka-topic",
    "key.converter": "org.apache.kafka.connect.storage.StringConverter",
    "value.converter": "org.apache.kafka.connect.storage.StringConverter",
    "value.converter.schemas.enable": "false",
    "beam.transform": "org.apache.beam.sdk.io.kafka.KafkaIO",
    "beam.format": "YOUR_BEAM_DATA_FORMAT"
  }
}

Make sure to replace "your-kafka-topic" with the name of your Kafka topic and "YOUR_BEAM_DATA_FORMAT" with the appropriate Beam data format, such as Avro, JSON, or Protobuf.

Step 3: Submitting the Connector

To submit the Kafka Source Connector to Kafka Connect, open a terminal and run the following command:

$ bin/connect-standalone.sh config/worker.properties kafka-source-connector.json

Make sure to adjust the paths and file names according to your Kafka Connect setup.

Step 4: Consuming Data in Apache Beam

Now that the Kafka Source Connector is up and running, we can consume the data in Apache Beam using the Java SDK. Here’s an example code snippet for reading data from Kafka and printing it to the console:

PipelineOptions options = PipelineOptionsFactory.create();
Pipeline pipeline = Pipeline.create(options);

pipeline.apply(KafkaIO.<String, String>read()
    .withBootstrapServers("localhost:9092")
    .withTopic("your-kafka-topic")
    .withKeyDeserializer(StringDeserializer.class)
    .withValueDeserializer(StringDeserializer.class)
    .withoutMetadata())
    .apply(ParDo.of(new DoFn<KV<String, String>, Void>() {
        @ProcessElement
        public void processElement(ProcessContext context) {
            String message = context.element().getValue();
            System.out.println(message);
        }
    }));

pipeline.run().waitUntilFinish();

Make sure to replace "localhost:9092" with the appropriate Kafka bootstrap servers and "your-kafka-topic" with the name of your Kafka topic.

Conclusion

Integrating Apache Beam with Apache Kafka Connect allows us to leverage the scalability and fault tolerance of Kafka with the rich data processing capabilities of Beam. By following the steps outlined in this blog post, you can seamlessly consume data from Kafka and process it using Apache Beam in a Java-based environment.

#apachebeam #apachekafka