kafkajs

What is kafkajs?

KafkaJS is a modern Apache Kafka client for Node.js. It is designed to be simple, reliable, and performant, making it easy to interact with Kafka brokers and manage Kafka topics, producers, and consumers.

What are kafkajs's main functionalities?

Producer

This code sample demonstrates how to create a Kafka producer using KafkaJS. The producer connects to the Kafka broker, sends a message to a specified topic, and then disconnects.

const { Kafka } = require('kafkajs');

const kafka = new Kafka({
  clientId: 'my-app',
  brokers: ['kafka1:9092', 'kafka2:9092']
});

const producer = kafka.producer();

const run = async () => {
  await producer.connect();
  await producer.send({
    topic: 'test-topic',
    messages: [
      { value: 'Hello KafkaJS user!' }
    ]
  });
  await producer.disconnect();
};

run().catch(console.error);

Consumer

This code sample demonstrates how to create a Kafka consumer using KafkaJS. The consumer connects to the Kafka broker, subscribes to a specified topic, and logs each message received.

const { Kafka } = require('kafkajs');

const kafka = new Kafka({
  clientId: 'my-app',
  brokers: ['kafka1:9092', 'kafka2:9092']
});

const consumer = kafka.consumer({ groupId: 'test-group' });

const run = async () => {
  await consumer.connect();
  await consumer.subscribe({ topic: 'test-topic', fromBeginning: true });

  await consumer.run({
    eachMessage: async ({ topic, partition, message }) => {
      console.log({
        partition,
        offset: message.offset,
        value: message.value.toString(),
      });
    },
  });
};

run().catch(console.error);

Admin

This code sample demonstrates how to use the admin client in KafkaJS to create a new topic. The admin client connects to the Kafka broker, creates a topic with specified configurations, and then disconnects.

const { Kafka } = require('kafkajs');

const kafka = new Kafka({
  clientId: 'my-app',
  brokers: ['kafka1:9092', 'kafka2:9092']
});

const admin = kafka.admin();

const run = async () => {
  await admin.connect();
  await admin.createTopics({
    topics: [
      { topic: 'test-topic', numPartitions: 1 }
    ]
  });
  await admin.disconnect();
};

run().catch(console.error);

Other packages similar to kafkajs

node-rdkafka

node-rdkafka is a high-performance Node.js client for Apache Kafka based on the C/C++ library librdkafka. It offers more advanced features and better performance compared to KafkaJS but can be more complex to set up and use.

kafka-node

kafka-node is another popular Kafka client for Node.js. It is simpler and easier to use compared to node-rdkafka but may not offer the same level of performance and advanced features as node-rdkafka or KafkaJS.

no-kafka

no-kafka is a pure JavaScript client for Apache Kafka. It is designed to be simple and easy to use, similar to KafkaJS, but it may not be as actively maintained or feature-rich as KafkaJS.

README

KafkaJS

A modern Apache Kafka® client for Node.js
Get Started »

Read the Docs · Report Bug · Request Feature

Table of Contents

• About the project
  • Sponsors
  • Features
  • Getting Started
    • Usage
• Contributing
  • Help Wanted
  • Contact
• License
  • Acknowledgements

About the Project

KafkaJS is a modern Apache Kafka client for Node.js. It is compatible with Kafka 0.10+ and offers native support for 0.11 features.

KAFKA is a registered trademark of The Apache Software Foundation and has been licensed for use by KafkaJS. KafkaJS has no affiliation with and is not endorsed by The Apache Software Foundation.

Sponsors ❤️

Upstash: Serverless Kafka True Serverless Kafka with per-request-pricing Managed Apache Kafka, works with all Kafka clients Built-in REST API designed for serverless and edge functions Start for free in 30 seconds!

Get help directly from a KafkaJS developer Become a Github Sponsor to have a video call with a KafkaJS developer Receive personalized support, validate ideas or accelerate your learning Save time and get productive sooner, while supporting KafkaJS! See support options!

To become a sponsor, reach out in our Slack community to get in touch with one of the maintainers. Also consider becoming a Github Sponsor by following any of the links under "Sponsor this project" in the sidebar.

Features

• Producer
• Consumer groups with pause, resume, and seek
• Transactional support for producers and consumers
• Message headers
• GZIP compression
  • Snappy, LZ4 and ZSTD compression through pluggable codecs
• Plain, SSL and SASL_SSL implementations
• Support for SCRAM-SHA-256 and SCRAM-SHA-512
• Support for AWS IAM authentication
• Admin client

Getting Started

npm install kafkajs
# yarn add kafkajs

Usage

const { Kafka } = require('kafkajs')

const kafka = new Kafka({
  clientId: 'my-app',
  brokers: ['kafka1:9092', 'kafka2:9092']
})

const producer = kafka.producer()
const consumer = kafka.consumer({ groupId: 'test-group' })

const run = async () => {
  // Producing
  await producer.connect()
  await producer.send({
    topic: 'test-topic',
    messages: [
      { value: 'Hello KafkaJS user!' },
    ],
  })

  // Consuming
  await consumer.connect()
  await consumer.subscribe({ topic: 'test-topic', fromBeginning: true })

  await consumer.run({
    eachMessage: async ({ topic, partition, message }) => {
      console.log({
        partition,
        offset: message.offset,
        value: message.value.toString(),
      })
    },
  })
}

run().catch(console.error)

Learn more about using KafkaJS on the official site!

• Getting Started
• A Brief Intro to Kafka
• Configuring KafkaJS
• Example Producer
• Example Consumer

Read something on the website that didn't work with the latest stable version?
Check the pre-release versions - the website is updated on every merge to master.

Contributing

KafkaJS is an open-source project where development takes place in the open on GitHub. Although the project is maintained by a small group of dedicated volunteers, we are grateful to the community for bug fixes, feature development and other contributions.

See Developing KafkaJS for information on how to run and develop KafkaJS.

Help wanted 🤝

We welcome contributions to KafkaJS, but we also want to see a thriving third-party ecosystem. If you would like to create an open-source project that builds on top of KafkaJS, please get in touch and we'd be happy to provide feedback and support.

Here are some projects that we would like to build, but haven't yet been able to prioritize:

• Dead Letter Queue - Automatically reprocess messages
• ✅ Schema Registry - Now available! thanks to @erikengervall
• Metrics - Integrate with the instrumentation events to expose commonly used metrics

Contact 💬

Join our Slack community

License

See LICENSE for more details.

Acknowledgements

• Thanks to Sebastian Norde for the V1 logo ❤️
• Thanks to Tracy (Tan Yun) for the V2 logo ❤️

Apache Kafka and Kafka are either registered trademarks or trademarks of The Apache Software Foundation in the United States and other countries. KafkaJS has no affiliation with the Apache Software Foundation.

Changelog

[2.2.4] - 2023-02-27

Added

• Include groupId in debug log when failing to find group coordinator #1522

Fixed

• Rejoin group after ILLEGAL_GENERATION error #1474
• Fix consumer getting stuck after very brief throttling #1532
• Prevent infinite crash loop when no brokers are available #1408