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Ubuntu Server 12.04. I use:

sudo crontab -e
* * * * * root /etc/init.d/apache2 restart > /dev/null 2>&1
sudo restart cron

And it doesnt work. How to fix it? So many docs in google,I need one "true way".

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What are you trying to achieve with this entry ? Using wildcards for everything seems weird. – alci Apr 3 '13 at 9:17
Wildcards for everything should be valid, but would result in it being called every 1 minute. – thomasrutter May 7 '15 at 0:34
@tim when you say it doesn't work, what happens? Is there anything in /var/log/syslog to show whether it executed and what error occurred? – thomasrutter May 7 '15 at 0:35
up vote 7 down vote accepted

I'm assuming that you have exited the cron tab after the 2nd statement. That third line won't work in crontab. Cron should reload itself.

The issue with your cron tab is that you have it set to run every minute of every hour of every day ect. That what the * means, all options.

View this in coumn format

` m - h  dom mon dow    command

* *   *   *   *       root /etc/init.d/apache2 restart > /dev/null 2>&1

You need

0  1  * * * root /etc/init.d/apache2 restart > /dev/null 2>&1

This is the the 0th minute of the 1st hour, every day.

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I use * * * * * root /etc/init.d/apache2 restart > /dev/null 2>&1 and it doesnt work – tim Apr 4 '13 at 9:22
You missed the entire point. You can't have 5 * in a row. – wlraider70 Apr 4 '13 at 19:22
0 1 * * * root /etc/init.d/apache2 restart > /dev/null 2>&1 - don't work. empty in logs – tim Apr 5 '13 at 11:14
You should have a log.. do this 1 * * * * service apache2 restart thus will set the job to hourly. – wlraider70 Apr 5 '13 at 15:31
/sbin/service <name> restart in case of centos6 – Tertium Dec 13 '15 at 1:07

Restart apache is a bad idea, maybe you can just reload? Or check apache status and restart if apache is down.

#!/usr/bin/env python
import urllib2
import commands
from subprocess import Popen

ip = ''
  link = urllib2.urlopen('http://%s' % ip).code
  print link
except urllib2.HTTPError as e:
  print e.code
except urllib2.URLError:

and cron job will be

*/5 * * * *

And first of all, when you want to restart apache in scripts, you must check configuration file for errors.

#!/usr/bin/env python
import re
from subprocess import check_output, call

def is_config_ok():
    if re.findall('OK',check_output('apache2ctl configtest', shell=True)):
        return 1
        return 0

if __name__ == "__main__":
    if is_config_ok():
        call('invoke-rc.d apache2 restart', shell=True)
        print "error in config"
share|improve this answer
missing import urllib2 – Pavel 'PK' Kaminsky Dec 9 '15 at 9:24

To become more familiar with the crontab timing commands you could try the Cron Sandbox.

Time/date parameters go in and a list of future run-times comes out.

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