aliekens / jruby-kafka

Jruby::Kafka

Prerequisites

• Apache Kafka version 0.8.1.1 installed and running.

• JRuby installed.

About

This gem is primarily used to wrap most of the Kafka 0.8.1.1 high level consumer and Kafka 0.8.1.1 producer API into jruby. The Kafka Consumer Group Example is pretty much ported to this library.

Installation

This package is now distributed via RubyGems.org but you can build it using the following instructions.

From the root of the project run:

$ bundle install
$ rake setup jar package

You can run the following to install the resulting package:

$ gem install jruby-kafka*.gem

Add this line to your application's Gemfile:

gem 'jruby-kafka'

Usage

If you want to run the tests, make sure you already have downloaded Kafka 0.8.X, followed the kafka quickstart instructions and have KAFKA_PATH set in the environment.

Usage

The following producer code sends a message to a test topic

require 'jruby-kafka'

producer_options = {:broker_list => "localhost:9092", "serializer.class" => "kafka.serializer.StringEncoder"}

producer = Kafka::Producer.new(producer_options)
producer.connect()
producer.send_msg("test", nil, "here's a test message")    

The following consumer example indefinitely listens to the test topic and prints out messages as they are received from Kafka:

require 'jruby-kafka'

consumer_options = {
  :topic_id => "test", 
  :zk_connect => "localhost:2181", 
  :group_id => "my_consumer_group", 
  :reset_beginning => "from-beginning", 
  :auto_offset_reset => "smallest"
}

consumer_group = Kafka::Group.new(consumer_options)
queue = SizedQueue.new(20)
consumer_group.run(1,queue)

count = 0
while true
  if !queue.empty?
    puts "#{count}\t#{queue.pop.message.to_s}"
    count += 1
  end
end

consumer_group.shutdown()

Using in logstash:

Check out this repo: https://github.com/joekiller/logstash-kafka

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request