-- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- - - - Jason Pyeron PD Inc. http://www.pdinc.us - - Principal Consultant 10 West 24th Street #100 - - +1 (443) 269-1555 x333 Baltimore, Maryland 21218 - - - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- This message is copyright PD Inc, subject to license 20080407P00.
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Timothy Murphy Sent: Wednesday, March 17, 2010 18:05 To: centos@centos.org Subject: Re: [CentOS] cron.hourly runs twice
Jason Pyeron wrote:
For some reason I cannot fathom, cron.hourly runs twice each hour on one of my two CentOS-5.4 systems,
Add this to the cron.hourly
#!/bin/sh pstree -up >> /tmp/foo.log
I tried this; the relevant lines on the first machine are:
|-crond(9167)-+-crond(9439)---run-parts(9441)-+-awk(9452) | | `-foo(9450)---pstree(9451) | `-crond(9440)---run-parts(9442)-+-awk(9455) | `-foo(9454)--- pstree(9456) |-cupsd(5301)---{cupsd}(17775)
and on the other CentOS machine:
Good, what I thought
|-crond(2824)---crond(28255)---run-parts(28256)---foo(28257)--- pstree(28258)
I've checked that /etc/rc.d/init.d/crond on the two machines are the same. So too is /etc/sysconfig/crond .
I'm not clear why crond starts another copy of crond, even on the second machine?
Please send output of:
for i in /etc/crontab /var/spool/cron/*; do echo $i && cat $i; done
-- Timothy Murphy e-mail: gayleard /at/ eircom.net tel: +353-86-2336090, +353-1-2842366 s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On a side note clock changes are not the issue:
Daylight Saving Time and other time changes
Local time changes of less than three hours, such as those caused by the start or end of Daylight Saving Time, are handled specially. This only applies to jobs that run at a specific time and jobs that are run with a granularity greater than one hour. Jobs that run more frequently are scheduled normally.
If time has moved forward, those jobs that would have run in the interval that has been skipped will be run immediately. Conversely, if time has moved backward, care is taken to avoid running jobs twice.
Time changes of more than 3 hours are considered to be corrections to the clock or timezone, and the new time is used immediately.