Date: Wed, 9 Aug 2000 05:00:02 -0700 (PDT) From: Neil Blakey-Milner <nbm@mithrandr.moria.org> To: freebsd-bugs@FreeBSD.org Subject: Re: conf/20498: All FreeBSD systems trigger massive late-night activity at the same times Message-ID: <200008091200.FAA03487@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR conf/20498; it has been noted by GNATS. From: Neil Blakey-Milner <nbm@mithrandr.moria.org> To: brett@lariat.org Cc: freebsd-gnats-submit@FreeBSD.org Subject: Re: conf/20498: All FreeBSD systems trigger massive late-night activity at the same times Date: Wed, 9 Aug 2000 13:56:23 +0200 On Wed 2000-08-09 (01:09), brett@lariat.org wrote: > >Number: 20498 > >Category: conf > >Synopsis: All FreeBSD systems trigger massive late-night activity at the same times > >Description: > All FreeBSD systems, for a very long time, have come with a fixed /etc/crontab > which triggers system security and statistics-gathering scripts at the same > time on each system. A room full of FreeBSD machines is a sight and sound to > behold at this "witching hour." The sudden churning of the hard drives, and the > slowdown in the entire network (especially if the machines are mail, news, or > Web servers) can be quite dramatic. So can the power surge; we see the load > indicators on our UPSes peak at that time. > >How-To-Repeat: > > >Fix: > It'd be a good idea to randomize the times at which these scripts are > triggered at install time. The run times should be distributed within > a 3-hour period -- say, from 2 to 5 AM. This is a system's administrator's job, surely? A gratuitous change like this by default will confuse and probably irritate many. And I personally wouldn't like to have to document it. One possible solution is to add a 000.time-wait.sh script to your periodic/daily directory, which has "perl -e 'sleep int(rand(180))' in it (overkill, I know). You can change '180' to get a number from a variable in periodic.conf, for example. It would default to 0, or something. If you don't want _each_ invocation randmomized, then make the number you get from a variable in periodic.conf be the exact offset. Neil -- Neil Blakey-Milner Sunesi Clinical Systems nbm@mithrandr.moria.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200008091200.FAA03487>