gistfile1.txt

  my $coll=$self->mango->db->collection('control');
  $coll->drop;
  $coll->create({capped=>\1, max=>2, size=>100});
  
  $self->{control} = $coll->find->tailable(1);
  $self->{control}->timeout(-1);
  my $cb;
  $cb= sub {
      my ($sub, $err,$doc) = @_;
      return $sub->next($cb) if $err;
      my $action = "ctrl_".$doc->{command};
      $self->$action($doc->{cid});
  };
  $self->{control}->next($cb);