Only received one reply to my question; thanks to Jim Belonis
(belonis_at_phys.washington.edu) for his reply. My original query (11/19):
> Hi all,
>
> I'm running a DEC v3.2. We use cron quite a bit, and in the
> afternoon we have it run a particular process every 10 minutes, starting
> at 5:05 PM local time and continuing every 10 minutes until 6:55 (this
> is correctly set up in the crontab). The curious thing is that quite
> often, it seems that cron "forgets" to launch the process! Sometimes
> it will begin at the next run time (5:15), but sometimes it misses
> several times (yesterday it didn't actually launch until 5:45, so it missed
> 4 chances).
Jim wondered if the job started but aborted early. I think not, since
we have an echo statement at the very beginning of the script which
we never see.
> I am wondering if this has anything to do with /var/adm/cron/queuedefs.
> Ours has an entry of "b.50j20n60w", which means that there are a maximum
> of 50 "batch" processes which can be run. If I do a ps -ef | wc -l
> around that time, the number is usually right around 50. Are all those
> processes "batch" processes?
Jim's reply:
No. That is ALL processes.
queuedefs is only used in conjunction with the 'batch' command
not cron jobs.
I've since read that queuedefs might not actually be used at all.
('batch' is similar to 'at' except the jobs run only if the load is low enough).
Jim also suggested that I check out the /usr/lib/cron/log file but it
doesn't show detailed messages regarding each cron-spawned process. Also
suggested was to turn on accounting to see every process which executed.
Haven't done this yet.
The particular cron job executes at the "5's" of hours 17 and 18. I've
since noticed that if it doesn't run at one time in the first hour,it
will also not run at the corresponding time in the second hour (e.g.,
1705 and 1805). I also enabled a dummy script which runs at the same
time which just echoes a line to a log file. Both jobs will either
run or not run at the same time.
It's a very erratic problem--sometime it happens and sometimes it doesn't.
Lately, I've enabled a dummy cron job which runs every two minutes at these
two hours--since I've done this, the problem hasn't occurred.
Any further advice/insight would be appreciated.
Thanks,
Kevin Tyle
MESO, Inc.
Received on Wed Dec 10 1997 - 18:01:30 NZDT