actually, it's not.
We create a special page, with PHP and one with nodejs, that just replies '1', so besides status, we also get a notice if nodejs or PHP malfunctions (which does happen on some servers, 1-2 time a year).
For example; you would do a head request and node.js and php would still need to be configured to handled the HEAD request but instead of its handler returning "1" it would simply return.