Publisher now running every 30 minutes

[Colin Watson]

Following some intensive optimisation work, the Ubuntu archive publisher
is now back [1] to running every 30 minutes, rather than on its previous
hourly cycle.  I hope this will help developers iterate fixes more
quickly, particularly when long dependency chains are involved.  We may
miss the odd run as we iron out the occasional problem with this setup,
but things are looking good so far; the last five runs have had more
than five minutes of clearance each.

[1] Long-timers may remember that before we switched the archive to
    Launchpad we were using dak on a 30-minute cycle; although the main
    thing optimised recently was actually something that would have
    affected dak too if we'd carried on running it for long enough with
    our setup.  See
    http://www.chiark.greenend.org.uk/ucgi/~cjwatson/blosxom/ubuntu/2011-10-24-quality-in-12-04.html.

Cheers,

-- 
Colin Watson                                       [cjwatson at ubuntu.com]