# client.rb

class Person
  include DataMapper::Resource
  include EMRPC::Pid

  after :update, :process_stats
  def process_stats
    StatServer.send(:process_stats, self, :stats_processed, person.attributes)
  end

  def stats_processed(result)
    # StatServer responded
  end
end

StatServer = EMRPC::ReconnectingPid.new('emrpc://localhost:4567/')

######################################################################

# server.rb

class StatServer
  include EMRPC::Pid
  def process_stats(pid, pid_callback, attributes)
    # do something ...
    # reply to pid:
    pid.send(pid_callback, {:answer => 42})
  end
end

EM::run do
  ss = StatServer.new
  ss.bind('emrpc://localhost:4567/')
end