Tuesday, 4 February 2014

Re: On-demand starting/stopping of cups [was: [Blueprint client-1305-printing-stack-with-mobile-in-mind] Printing Stack with Mobile in Mind]

Oliver Grawert [2014-02-04 18:21 +0100]:
> but as i understand the cups architecture even that needs the locally
> running server anyway

For the record, it doesn't *need* it. If you add your print server
address to /etc/cups/client.conf, the only thing that you need locally
is libcups*. But then your print server really needs to be available
each time you print a job, i. e. if you have a non-permanent network
or sometimes shut down the print server printing would fail. With a
local cupsd your jobs get queued instead, and then sent to the print
server once it becomes available.

That's why you run with a local spooler (cupsd) *usually*. But in an
office environment with ethernet and always running servers it's quite

> i personally just don't get why we cant make cups stop even on the
> desktop unless the machine is an actual printserver, the additional
> startup time will be minor on a modern desktop/laptop PC. i doubt
> people would even notice that their print job takes a few seconds
> longer than it would with a permanently running daemon.

Yes, agreed. I'm not concerned about cups' start up time, that's
negligible. I'm primarily concerned about the time that it takes to
detect remote printers, as they are only advertised/broadcast every so
often (30s?). For that I think we ought to have at least avahi running
permanently, so that it can pick up remote services and then when
cups/cups-browsed get activated they can immediately use remote
printers. That assumes that it's actually avahi-daemon which
stores/caches those; if that's not the case, then cups-browsed needs
to run all the time instead.


Martin Pitt | http://www.piware.de
Ubuntu Developer (www.ubuntu.com) | Debian Developer (www.debian.org)