Custom Query (1145 matches)

Reported by broder, 14 years ago.

Right now, several of the scripts in /etc/X11/Xsession.d use dpkg-query -W -f '${Status}' PACKAGE to test if a package is installed.

This is necessary because conffiles are not removed when a package is uninstalled (only when it's purged), and Debian Policy dictates that a conffile cause no change when the package is uninstalled (it's only kept so that the configuration can be restored should the package be installed in the future).

However, using dpkg-query requires loading the entire dpkg database into buffer cache, which is a slow process, at least the first time, and happens at a point where there's already lots of disk I/O happening. Looking at bootcharts, it generally takes about 2 seconds. Because that query has to finish before the script can determine whether to do anything, it blocks the login time.

Instead of using dpkg-query, all of those scripts should be changed to use a finer-grained test. For instance, the debathena-larvnet script could check for [ -x /usr/lib/debathena-larvnet/larvnet-wrapper ], which is much less filesystem-intensive.

Reported by jdreed, 14 years ago.

We need a somewhat reliable hook for when machines explode. This can be something like:

• a script in AFS that gets sourced at boot time (and thus any failure is as simple as "reboot the machine")
• a script in AFS that gets sourced by cron periodically
• a script in AFS that gets sourced by auto-update (to fix things prior to an update).

This could potentially also minimize the need for us to do stupid version-specific things in maintainer scripts when we screw up.

Reported by geofft, 14 years ago.

We're currently not getting all the updates because ttf-mscorefonts-installer is (re?)prompting for the license. auto-update should preseed acceptance of the license.