Hi, On 2015-03-07 18:16, sgofferj wrote: > On my main server I see unexplainable time jumps backwards in the syslog. > Those jumps affect CRON. > Example: > > Feb 10 06:48:01 nostromo CRON[20351]: (root) CMD ( > /storage/exec/checkinternet.sh 2>/dev/null 1>/dev/null) > Feb 10 06:49:01 nostromo CRON[20364]: (root) CMD ( > /storage/exec/checkinternet.sh 2>/dev/null 1>/dev/null) > Feb 10 06:50:01 nostromo CRON[20386]: (root) CMD ( > /storage/exec/status-nostromo.sh >/dev/null 2>&1) > Feb 7 05:40:01 nostromo CRON[20389]: (root) CMD ( > /storage/exec/checkinternet.sh 2>/dev/null 1>/dev/null) > Feb 10 06:50:01 nostromo CRON[20390]: (root) CMD ( > /storage/exec/checkinternet.sh 2>/dev/null 1>/dev/null) > Feb 10 06:50:01 nostromo CRON[20391]: (root) CMD ( > /storage/exec/checkip.sh 2>/dev/null 1>/dev/null)
I'm afraid this is not a cron bug. The cron daemon does not write any logs itself: as it is customary, it uses the syslog(3) facilities to log all its messages. Therefore, the timestamp you are seeing is not generated by cron, but by your syslog daemon. Note that the PIDs of the individual cron processes are close together (20386, 20389, 20390, 20391), which usually indicates that they were started in close succession. So, despite the bogus timestamp, your cron execution schedule appears to be fine. I'd say this is either a bug in your syslog implementation, or a hardware issue affecting syslog. By reassigning this bug to your syslog implementation, the respective maintainers might be able to help you in tracking down this issue. Regards, Christian > For debugging I did the following: > Start xclock and watch xclock and tail -f /var/log/syslog in parallel. When > CRON logged a wrong time, xclock did NOT show any time jump but seemed to > freeze for a fraction of a second. > Open a screen and start a script that will once per second read the time (in > unix seconds) and compare the read time with the time read a second ago. If > the current time was smaller, the script would send an email with a process > list from before and after the jump. The script also never detected any time > jump. > > In summary, my current impression is that there might be a bug in CRON > because no other programm seems to be able to see the "wrong" time. The > server in question is syslog server for 4 servers and 3 network devices. The > time jumps exclusively show in syslog entries from the local CRON instance. > Not in any remote syslog entry and not in any other local syslog entry, e.g. > from DHCPD, bind, tftpd, etc. etc. > Also, after a reboot, things work ok for several days upto about 2 or 3 > weeks. Then the "time jumps" start to occur with increasing frequency. > > I don't use user crontabs but maintain all jobs in /etc/crontab. I have > number of jobs which are triggered every minute and another number of > jobs which are triggered every 5 minutes (maybe some CRON internal > counter overflow problem?). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1429427 Title: Unexplainable time jumps in CRON To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cron/+bug/1429427/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
