I have a custom site-wide block that shows on all pages, which I would like to be heavily cached for anon users but able to be invalidated when I modify its settings, or en/disable it (both drupal variables set in an admin page).
I've managed to achieve this pretty nicely in D8 with
Cache::invalidateTags(), as well as some custom Acquia stuff to invalidate the varnish cache. However in trying to port this same functionality to a D7 site I've not managed to find any good method of doing it.
Any help much appreciated, thanks in advance!