On Thu 05 Apr 2018 at 14:35:02 -0400, Stefan Monnier wrote:
> Package: cups-browsed
> Version: 1.20.1-1+b1
> Severity: normal
>
> Here's a sample session:
>
> # ps auxw|grep cups
> root 27143 0.0 0.1 19508 9600 ?Ss Apr040:07
> /usr/sbin/cupsd -l
> root 27144 0.0 0.1 42080 11184 ?Ssl Apr04 0:00
> /usr/sbin/cups-browsed
> root 31856 0.0 0.0 5284 876 pts/5RN+ 14:27 0:00 grep cups
> ~-0# /etc/init.d/cups stop;/etc/init.d/cups start
> [ ok ] Stopping cups (via systemctl): cups.service.
> [ ok ] Starting cups (via systemctl): cups.service.
> ~-0# ps auxw|grep cups
> root 31935 0.0 0.0 17516 6932 ?Ss 14:28 0:00
> /usr/sbin/cupsd -l
> root 31954 0.0 0.0 5284 796 pts/5SN+ 14:28 0:00 grep cups
> ~-0#
>
> As you can see before the `cups stop; cups start` both `cupsd` and `cups-
> browsed` were running, whereas afterwards only `cupsd` is running.
Interactions between systemd, cups and cups-browsed are well above my
pay grade but I'll try to shed some light on the behaviour.
> I believe this behavior is incorrect since no part of `cups stop; cups start`
> says explicitly that we want `cups-browsed` to be stopped. So either `cups
Indeed. cup.service does not ask for or mandate that cups-browsed be
stopped. However, cups-browsed.service has the line
Requires=cups.service
and it will stop itself if cupsd becomes unavailable. So it is not
really anything to do with cups. cups is responsible for itself, as is
cups-browsed responsible for its own management.
>From the cups-filters Debian changelog:
> - cups-browsed: Added "Requires=cups-service" to the cups-browsed.service
> file, so that systemd keeps CUPS running while shutting down cups-browsed
> on system shutdown (LP: #1579905)
I think cups-browsed is seen as having no function if cupsd is not
running.
> stop` should not stop `cups-browsed`, or it should check if `cups-browsed` is
> running and arrange to make sure a subsequent `cups start` restarts it if
> applicable.
I've explained why cups has no responsibility for stopping cups-browsed.
What I cannot explain or argue is whether cups.service should become
resonsible for (re)starting another service when that service itself
decides to shut down.
I observe on unstable that the commands 'cupsctl --debug-logging' and
'apt --reinstall install cups-daemon' stop cupsd and cups-browsed but
cups-browsed gets restarted in both cases. (The Main PIDs change).
--
Brian.
