sunspot_rails gem – “ Errno:: ECONNREFUSED (Connection refused – connect (2)) ”-Collection of common programming errors

I use gem sunspot_rails https://github.com/outoftime/sunspot I did everything according to the instructions on http://railscasts.com/episodes/278-search-with-sunspot, but get an error

Errno:: ECONNREFUSED (Connection refused – connect (2)): app/controllers/books_controller.rb: 7: in `index ‘

code from books_controller.rb

  def index
    @search = Book.search do
      fulltext params[:search]
    end
    @books = @search.results
  end

what it can be? Thanks.