Linux – Crontab running when it pleases (fixed.. in a way)

cronlinuxphp5Ubuntu

I have the following line in the crontab:

 */30 * * * * /usr/bin/php /home/antoniocs/phpscripts/update-noip/update-noip.php

This script updates my no-ip account. It also writes to a log file saying what it did and did not due.

This is today's log file:

2009/08/06 11:30 - A tentar buscar ip
2009/08/06 11:30 - Ip encontrado - ***.***.***.***
2009/08/06 11:30 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 12:00 - A tentar buscar ip
2009/08/06 12:00 - Ip encontrado - ***.***.***.***
2009/08/06 12:00 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 12:30 - A tentar buscar ip
2009/08/06 12:30 - Ip encontrado - ***.***.***.***
2009/08/06 12:30 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 13:00 - A tentar buscar ip
2009/08/06 13:00 - Ip encontrado - ***.***.***.***
2009/08/06 13:00 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 13:30 - A tentar buscar ip
2009/08/06 13:30 - Ip encontrado - ***.***.***.***
2009/08/06 13:30 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 14:00 - A tentar buscar ip
2009/08/06 14:00 - Ip encontrado - ***.***.***.***
2009/08/06 14:00 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 14:30 - A tentar buscar ip
2009/08/06 14:30 - Ip encontrado - ***.***.***.***
2009/08/06 14:30 - Ip nao alterado - Abortar acesso ao no-ip
2009/08/06 15:00 - A tentar buscar ip
2009/08/06 15:00 - Ip encontrado - ***.***.***.***
2009/08/06 15:00 - Ip nao alterado - Abortar acesso ao no-ip

As you can see by the timestamp, today it started at 11:30 and then stopped and 15:00.

Also the cron is running:

antoniocs@acsserver:~$ /etc/init.d/cron status
 * cron is running

I don't know why this is happening. Some days ago this was running with out a problem (I have entries in the log every 30m). The only thing I did was recently upgrade my Ubuntu-Server (which has caused me some other problems)

Am I doing anything wrong here? Have the updates messed up cron??

EDIT:

This is what I have in the syslog for 7/8/09 at 15:00 (This is today's log but the same thing happened it stopped after 15:00)

146 Aug  7 15:00:01 acsserver CRON[30775]: Mount of private directory return code [0]
147 Aug  7 15:00:01 acsserver /USR/SBIN/CRON[30786]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
148 Aug  7 15:00:01 acsserver /USR/SBIN/CRON[30811]: (antoniocs) CMD (/usr/bin/php /home/antoniocs/phpscripts/update-noip/update-noip.php )
149 Aug  7 15:00:01 acsserver /USR/SBIN/CRON[30810]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd hourly 2>/dev/null)

There doesn't seem to be any errors 🙁

EDIT 2:
After looking at the syslog file I noticed these lines:

Aug  7 22:10:01 acsserver /USR/SBIN/CRON[6023]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
Aug  7 22:17:01 acsserver /USR/SBIN/CRON[6158]: (root) CMD (   cd / && run-parts --report /etc/cron.hourly)
Aug  7 22:20:01 acsserver /USR/SBIN/CRON[6207]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
Aug  7 22:30:01 acsserver CRON[6336]: Mount of private directory return code [256]
Aug  7 22:30:01 acsserver /USR/SBIN/CRON[6350]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
Aug  7 22:30:01 acsserver /USR/SBIN/CRON[6354]: (antoniocs) CMD (/usr/bin/php /home/antoniocs/phpscripts/update-noip/update-noip.php )
Aug  7 22:30:01 acsserver postfix/sendmail[6367]: fatal: open /etc/postfix/main.cf: No such file or directory
Aug  7 22:39:01 acsserver /USR/SBIN/CRON[6523]: (root) CMD (  [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 | xargs -n 200 -r -0 rm)
Aug  7 22:40:01 acsserver /USR/SBIN/CRON[6574]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
Aug  7 22:50:01 acsserver /USR/SBIN/CRON[7044]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
Aug  7 23:00:01 acsserver CRON[7173]: Mount of private directory return code [256]
Aug  7 23:00:01 acsserver /USR/SBIN/CRON[7193]: (antoniocs) CMD (/usr/bin/php /home/antoniocs/phpscripts/update-noip/update-noip.php )
Aug  7 23:00:01 acsserver /USR/SBIN/CRON[7195]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd hourly 2>/dev/null)
Aug  7 23:00:01 acsserver /USR/SBIN/CRON[7196]: (root) CMD ([ -x /usr/sbin/update-motd ] && /usr/sbin/update-motd 2>/dev/null)
Aug  7 23:00:01 acsserver postfix/sendmail[7211]: fatal: open /etc/postfix/main.cf: No such file or directory
Aug  7 23:09:01 acsserver /USR/SBIN/CRON[7390]: (root) CMD (  [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 | xargs -n 200 -r -0 rm)

So it is running the php script.
I just don't know what /etc/postfix/main.cf is. In my php script I only use curl to make some connections.

EDIT 3:

Seems that the problem really was the postfix.
I followed these instructions -> https://help.ubuntu.com/7.04/server/C/postfix.html
and just set up the main.cf file that the cron was complaining about and the php script now seems to be okay.

Still don't fully understand why this was happening. If anyone has any theory on why the heck this happened and why I needed the postfix to run my php script, please let me know!!

Thanks for all the help guys!

PS: Also if anyone knows what the mount error is please also tell me 🙁

Best Answer

Your final "EDIT 2" logfile shows that your postfix system isn't set up properly. When a cron script sends output to stdout or stderr (eg, any error messages in the script) , it sends an email (to root@localhost by default), and you need a working mail server for that to happen.

It looks very much like your script is failing for some other reason and is writing something to stderr or stdout, but because you don't have a working postfix setup you're losing that information. It's quite likely those error emails have the information you need to work out why your script is failing.

That, of course, is assuming this isn't your error: Aug 7 22:30:01 acsserver CRON[6336]: Mount of private directory return code [256]

Either way, you should fix your postfix setup.

Related Solutions

Linux – Job scheduling using crontab, what will happen when computer is shutdown during that time

When your computer is shut down (or the cron daemon is otherwise not running), cron jobs will not be started.

If you have jobs that you would like to run after the fact during those times when the computer is shut down, use anacron. Installed by default, see "man anacron", "man anacrontab", or the file /etc/anacrontab for more info.

Ubuntu uses anacron by default for crontab entries in:

/etc/cron.daily
/etc/cron.weekly
/etc/cron.monthly

leaving the remaining crontabs to be handled by the main cron daemon, specifically:

/etc/crontab
/etc/cron.d
/var/spool/cron

NOTES

Anacron itself does not run as a daemon, but relies on system startup scripts and cron itself to run.

On the Ubuntu 8.04 box I'm looking at, /etc/init.d/anacron is run at boot, and again by cron each morning at 07:30.

The README at /usr/share/doc/anacron/README.gz has a slight bit more info than is contained in the manpages.

EXAMPLES

For simple "daily", "weekly", "monthly" jobs, put a copy of or a symlink to the script in one of the /etc/cron.{daily|weekly|monthly} directories above. Anacron will take care of running it daily/weekly/monthly, and if your computer is off on the day the "weekly" scripts would normally run, it'll run them the next time the computer is on.

As another example, assuming you have a script here: /usr/local/sbin/maint.sh

And you wish to run it every three days, the standard entry in /etc/crontab would look like this:

# m h dom mon dow user  command
0 0 */3 * * root /usr/local/sbin/maint.sh

If your computer was not on at 00:00 on the 3rd of the month, the job would not run until the 6th.

To have the job instead run on the 4th when the computer is off and "misses" the run on the 3rd, you'd use this in /etc/anacrontab (don't forget to remove the line from /etc/crontab):

# period delay job-identifier command
3 5 maint-job /usr/local/sbin/maint.sh

The "delay" of "5" above means that anacron will wait for 5 minutes before it runs this job. The idea is to prevent anacron from firing things off immediately at boot time.

Linux – MySQL server CPU usage shot up for no apparent reason. Any idea why

Does this MySQL server manage a database for a public facing website?

Middle of the night CPU spikes can sometimes correlate to search engine bots indexing a large number of pages. Check to see if your access logs/analytics on your web servers match up.

Best Answer

Related Solutions

Linux – Job scheduling using crontab, what will happen when computer is shutdown during that time

Linux – MySQL server CPU usage shot up for no apparent reason. Any idea why

Related Topic