ruby_threads_forks.rb

batches = Queue.new
Order.select(:id).find_in_batches do |batch|
  batches << batch.map(&:id)
end
cpu_available.times do
  Thread.new do
    while(ids = batches.pop)
      pid = Process.fork do
        Sunspot.index! Order.includes(:product).find(ids)
      end
      Process.wait(pid)
    end
  end
end
Thread.new do
  sleep 1 until batches.size.zero?
end.join
Process.waitall