I have three services: postgresql, pgpool, and apache.
It's trivial to set up a restart for apache if its conf files or package change.
But when pgpool's conf file or package change, I have to ensure apache is *stopped* before, and *restarted* after, because apache holds persistent connections to pgpool.
Likewise, when postgresql's conf or package change, I need to ensure *both* pgpool *and* apache are stopped and restarted in an outer to inner order.
What's the easiest way to describe this in the SLS?