[arch-general] Replace dcron once again?
lisaev at umail.iu.edu
Sat Nov 13 22:07:59 CET 2010
On (11/13/10 18:57), Vincent Cappe wrote:
-~> Allan McRae <allan at archlinux.org> wrote:
-~> > Surely someone can run a git bisect on this issue. It is a reasonably
-~> > new occurrence.
-~> Except that the @daily bug only trigger every 24 hours or so. A little
-~> too time consuming for git bisect, i would say.
-~> But, there is a way around this: overriding the libc time() and
-~> localtime() functions with LD_PRELOAD to trick crond into thinking
-~> time passes quicker than it actually do. libfaketime can do
-~> this. So you can launch crond with something like this (as root):
-~> # faketime -f '+0 x30'./crond -s /tmp/systabs -c /tmp/usertabs -t /tmp/stamps -d
-~> which will make @hourly happen about every two minutess and @daily about
-~> every 48 minutes. note: using x60 and above will utterly confuse crond
-~> (Not a Bug), so don't do that.
-~> Combine with a crontab like this:
-~> @hourly ID=hourly echo "HOURLY $(date)" >> /tmp/dcron-test
-~> @daily ID=daily echo "DAILY $(date)" >> /tmp/dcron-test
-~> @weekly ID=weekly echo "WEEKLY $(date)" >> /tmp/dcron-test
-~> @monthly ID=monthly echo "MONTHLY $(date)" >> /tmp/dcron-test
-~> You can then monitor /tmp/dcron-test and see if jobs are scheduled
-~> Also the TZ environment variable can be useful (see 'info libc tz').
-~> But, i was not able to reproduce the "@hourly run only once every
-~> two hours" problem with neither TZ=FOO-1BAR-2,N10,N350 , nor
-~> 'export TZ=:/usr/share/zoneinfo/Europe/Paris; faketime -f -60d ./crond ... -d'.
-~> So, it seems DST alone is not enough to trigger it. Presumably, it
-~> also depends upon the content of the timestamp files ?
-~> I never saw the @daily bug, personally.
-~>  http://www.code-wizards.com/projects/libfaketime/index.html
-~>  http://aur.archlinux.org/packages.php?ID=24381
-~> Sent thru gmane, let's see if it works.
And I don't recall seeing any of this with dcron 4.4-1. I have fcron
installed everywhere, so... but as long as you seem to be playing with this,
could you please try with 4.4-1? It should be available through SVN...
lisaev at svibor
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