Poseidon

Poseidon is a Kafka client. Poseidon only supports the 0.8 API and above.

Until 1.0.0 this should be considered ALPHA software and not neccessarily production ready.

Usage

API Documentation

Installing a Kafka broker locally

Follow the instructions on the Kafka wiki to build Kafka 0.8 and get a test broker up and running.

Sending messages to Kafka

require 'poseidon'

producer = Poseidon::Producer.new(["localhost:9092"], "my_test_producer")

messages = []
messages << Poseidon::MessageToSend.new("topic1", "value1")
messages << Poseidon::MessageToSend.new("topic2", "value2")
producer.send_messages(messages)

More detailed Poseidon::Producer documentation.

Fetching messages from Kafka

require 'poseidon'

consumer = Poseidon::PartitionConsumer.new("my_test_consumer", "localhost", 9092,
                                            "topic1", 0, :earliest_offset)

loop do
  messages = consumer.fetch
  messages.each do |m|
    puts m.value
  end
end

More detailed Poseidon::PartitionConsumer documentation.

Using snappy compression

To use snappy compression in your producers or consumers, install the snappy gem or simply add gem 'snappy' to your project's Gemfile.

Semantic Versioning

This gem follows SemVer. In particular, the public API should not be considered stable and anything may change without warning until Version 1.0.0. Additionally, for the purposes of the versioning the public API is everything documented in the public API docs.

Requirements

Ruby 1.9.3 or higher (1.9.2 and below not supported!!!)
Kafka 0.8 or higher

Integration Tests

In order to run integration tests you must specify a KAFKA_PATH environment variable which points to a built Kafka installation. To build Kafka locally follow the instructions provided by the project.

# cd ~/src/poseidon/
# bundle
# KAFKA_PATH=~/src/kafka bundle exec rake spec:all # run all unit and integration specs

The poseidon test suite will take care of spinning up and down the broker(s) needed for the integration tests.