Exemplo de onde se usaria o retry junto com a cláusula rescue.

example_rescue_with_retry.rb

require 'open-uri'

tries = 0

begin
  tries += 1
  open("http://norbaoliveira.com") { |f| puts f.readlines }
rescue OpenURI::HTTPError => e
  puts e.message
  if tries < 4
    sleep(2**tries)
    retry
  end
end