Toiler

Toiler is a AWS SQS long-polling thread-based message processor. It's based on shoryuken but takes a different approach at loadbalancing and uses long-polling.

Features

Concurrency

Toiler allows to specify the amount of processors (threads) that should be spawned for each queue. Instead of shoryuken's loadbalancing approach, Toiler delegates this work to the kernel scheduling threads.

Long-Polling

A Fetcher thread is spawned for each queue. Fetchers are resposible for polling SQS and retreiving messages. They are optimised to not bring more messages than the amount of processors avaiable for such queue. By long-polling fetchers wait for a configurable amount of time for messages to become available on a single request, this prevents unneccesarilly requesting messages when there are none.

Message Parsing

Workers can configure a parser Class or Proc to parse an SQS message body before being processed.

Batches

Toiler allows a Worker to be able to receive a batch of messages instead of a single one.

Auto Visibility Extension

Toiler has the ability to automatically extend the visibility timeout of and SQS message to prevent the message from re-entering the queue if processing of such message is taking longer than the queue's visibility timeout.

Instalation

Add this line to your application's Gemfile:

gem 'toiler'

And then execute:

$ bundle

Or install it yourself as:

$ gem install toiler

Usage

Worker class

class MyWorker
  include Toiler::Worker

  toiler_options queue: 'default', concurrency: 5, auto_delete: true
  toiler_options parser: :json

  # toiler_options parser: ->(sqs_msg){ REXML::Document.new(sqs_msg.body) }
  # toiler_options parser: MultiJson
  # toiler_options auto_visibility_timeout: true
  # toiler_options batch: true

  #Example connection client that should be shared across all instances of MyWorker
  @@client = ConnectionClient.new

  def initialize
    @last_message = nil
  end

  def perform(sqs_msg, body)
    #Workers are thread safe, yay!
    #Each worker instance is assured to be processing only one message at a time
    @last_message = sqs_msg 
    puts body
  end
end

Configuration

aws:
  access_key_id:      ...       # or <%= ENV['AWS_ACCESS_KEY_ID'] %>
  secret_access_key:  ...       # or <%= ENV['AWS_SECRET_ACCESS_KEY'] %>
  region:             us-east-1 # or <%= ENV['AWS_REGION'] %>
wait: 20                        # The time in seconds to wait for messages during long-polling

Rails Integration

You can tell Toiler to load your Rails application by passing the -R or --rails flag to the "toiler" command.

If you load Rails, and assuming your workers are located in the app/workers directory, they will be auto-loaded. This means you don't need to require them explicitly with -r.

Start Toiler

bundle exec toiler -r worker.rb -C toiler.yml

Other options:

toiler --help

    -d, --daemon                     Daemonize process
    -r, --require [PATH|DIR]         Location of the worker
    -q, --queue QUEUE1,QUEUE2,...    Queues to process
    -C, --config PATH                Path to YAML config file
    -R, --rails                      Load Rails
    -L, --logfile PATH               Path to writable logfile
    -P, --pidfile PATH               Path to pidfile
    -v, --verbose                    Print more verbose output
    -h, --help                       Show help

Credits

Sebastian Schepens for the creation of the proyect. But much of the credit goes to Pablo Cantero, creator of Shoryuken, and everybody who contributed to it.

Contributing

1. Fork it ( https://github.com/sschepens/toiler/fork )
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 a new Pull Request