[systemd-devel] Examples to distinguish Before=/After= and Wants=/Requires=/BindsTo=

[Kenneth Porter]

--On Friday, September 17, 2021 12:49 PM +0200 Lennart Poettering 
<lennart at poettering.net> wrote:

> more specific example: you can use apache without mysql, and you can
> use mysql without apache, but quite often they are used together, and
> if so you likely want to start mysql first, and apache second, since
> it likely consumes services of mysql, and not the other way
> round. Hence in this example, you'd place an ordering dep, but not
> requirement dep.

Would such an ordering dependency without a requirements dependency allow 
apache to start without mysql? Or does an ordering dependency imply a 
requirements dependency? In which case, could systemd automatically infer 
the requirements from the ordering?