Define what topics you want to consume with which consumers in karafka.rb

Karafka::App.routes.draw do topic ‘system_events’ do

consumer EventsConsumer

end end

And create your consumers, within which your messages will be processed

class EventsConsumer < ApplicationConsumer # Example that utilizes ActiveRecord#insert_all and Karafka batch processing def consume

# Store all of the incoming Kafka events locally in an efficient way
Event.insert_all messages.payloads

end end

Karafka **uses** threads to handle many messages simultaneously in the same process. It does not require Rails but will integrate tightly with any Ruby on Rails applications to make event processing dead simple.

## Getting started

![karafka web ui](https://raw.githubusercontent.com/karafka/misc/master/printscreens/web-ui.png)

If you're entirely new to the subject, you can start with our "Kafka on Rails" articles series, which will get you up and running with the terminology and basic ideas behind using Kafka:

- [Kafka on Rails: Using Kafka with Ruby on Rails – Part 1 – Kafka basics and its advantages](https://mensfeld.pl/2017/11/kafka-on-rails-using-kafka-with-ruby-on-rails-part-1-kafka-basics-and-its-advantages/)
- [Kafka on Rails: Using Kafka with Ruby on Rails – Part 2 – Getting started with Rails and Kafka](https://mensfeld.pl/2018/01/kafka-on-rails-using-kafka-with-ruby-on-rails-part-2-getting-started-with-ruby-and-kafka/)

If you want to get started with Kafka and Karafka as fast as possible, then the best idea is to visit our [Getting started](https://karafka.io/docs/Getting-Started) guides and the [example apps repository](https://github.com/karafka/example-apps).

We also maintain many [integration specs](https://github.com/karafka/karafka/tree/master/spec/integrations) illustrating various use-cases and features of the framework.

### TL;DR (1 minute from setup to publishing and consuming messages)

**Prerequisites**: Kafka running. You can start it by following instructions from [here](https://karafka.io/docs/Setting-up-Kafka).

1. Add and install Karafka:

```bash
# Make sure to install Karafka 2.4
bundle add karafka --version ">= 2.4.0"

bundle exec karafka install

1. Dispatch a message to the example topic using the Rails or Ruby console:

Karafka.producer.produce_sync(topic: 'example', payload: { 'ping' => 'pong' }.to_json)

1. Run Karafka server and see the consumption magic happen:

bundle exec karafka server

[86d47f0b92f7] Polled 1 message in 1000ms
[3732873c8a74] Consume job for ExampleConsumer on example started
{"ping"=>"pong"}
[3732873c8a74] Consume job for ExampleConsumer on example finished in 0ms