Solved

Crontab: Set to run every hour but runs every 15 minutes. Why?

Posted on 2012-03-16
14
705 Views
Last Modified: 2012-06-27
I have the following set in /etc/crontab

40 * * * * root wget -q -O - 'http://www.mydomain.info/script.php' >/dev/null

Open in new window

To me this command should run every hour at +40 minutes.

For some reason though it runs every 15 minutes.

Can anybody see why?
0
Comment
Question by:AdrianSmithUK
  • 6
  • 5
  • 3
14 Comments
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 37728976
Comment deleted.

wmp
0
 

Author Comment

by:AdrianSmithUK
ID: 37728985
Dear woolmilkporc

That's not what you told me in this post - See accepted solution.

http://www.experts-exchange.com/OS/Linux/Q_26977577.html
0
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 37728991
That's why I deleted my comment - I was totally on the wrong track - don't have much time at this very moment.
0
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 37729016
Sorry again, I obviously confused root's crontab with the system crontab - I've been in a hurry.

Now that our meeting has been cancelled I'm back.

Your cron job should indeed run every 40 minutes. I don't see any obvious reason why it should do something else.

Maybe you should restart the cron daemon, just to be sure?
0
 
LVL 11

Expert Comment

by:legolasthehansy
ID: 37729030
Check as root - "crontab -l"
See if the changes you made reflect on the Cron.
0
 

Author Comment

by:AdrianSmithUK
ID: 37729031
Nice to have you back.

I had is set to:

0 * * * *

And it fired every 15 minutes from the hour. (10:00,  10:15 ...etc)

I changed it to

40 * * * *

Now it fires like this (11:40, 11:55 ...etc)
0
 

Author Comment

by:AdrianSmithUK
ID: 37729045
Dear legolasthehansy

[root ~]# crontab -l
[root ~]# 

Open in new window


I'm using Centos 6. When I run the command I get nothing.
0
What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

 
LVL 11

Assisted Solution

by:legolasthehansy
legolasthehansy earned 250 total points
ID: 37729049
Strange!

Check Cron logs.
Recreate the cron by deleting the entries and restarting CRON and then re-entering it.
Check if another user is running the same script using cron.
0
 
LVL 68

Expert Comment

by:woolmilkporc
ID: 37729053
"crontab -l" would only work on root's crontab, not on /etc/crontab

Same confusion as mine before.

Did you recycle crond?
0
 

Author Comment

by:AdrianSmithUK
ID: 37729088
Dear legolasthehansy

I looked in /var/log/cron

There is only a record for the hourly cron jobs.

I have Plesk installed. Do you think it could be to blame?
0
 
LVL 68

Assisted Solution

by:woolmilkporc
woolmilkporc earned 250 total points
ID: 37729145
I once read a bug report saying that an empty line just above a job entry could inhbit the correct scheduling of the job.

Could this be the culprit here?
0
 
LVL 11

Expert Comment

by:legolasthehansy
ID: 37729147
Not sure if Plesk has a utility to setup CRON's. But it should still show up on the files.

If you know the users allowed to access this server,
can you do this,

crontab -l <username1> (This would list the CRON's setup by username1)

You can get the list of users in the server by doing a cat on /etc/passwd and get the list of recent logged in users using the 'last' command.
0
 

Accepted Solution

by:
AdrianSmithUK earned 0 total points
ID: 37729376
Chaps,

Thanks for your help.

I never found the solution to the original problem. I tried removing the spare lines, but still had the same problem.

I noticed that plesk runs a backup manager every 15 minutes which might be a clue.

Mar 16 13:16:01 sXXXXXXXX CROND[3453]: (root) CMD ([ -x /usr/local/psa/admin/sbin/backupmng ] && /usr/local/psa/admin/sbin/backupmng >/dev/null 2>&1)
Mar 16 13:31:01 sXXXXXXXX CROND[3453]: (root) CMD ([ -x /usr/local/psa/admin/sbin/backupmng ] && /usr/local/psa/admin/sbin/backupmng >/dev/null 2>&1)

Open in new window



In the end I gave up and I used the built in plesk feature.

http://myhosting.com/kb/How_to_Set_Up_Scheduled_Tasks_(Cron_Jobs)_in_Plesk_10

I couldn't get it to work though.

In the end I found the problem was that SSH access was switched off for the domain.

Here is the solution:

http://drupal.org/node/1192934
0
 

Author Closing Comment

by:AdrianSmithUK
ID: 37746272
Great Support!
0

Featured Post

How to improve team productivity

Quip adds documents, spreadsheets, and tasklists to your Slack experience
- Elevate ideas to Quip docs
- Share Quip docs in Slack
- Get notified of changes to your docs
- Available on iOS/Android/Desktop/Web
- Online/Offline

Join & Write a Comment

Suggested Solutions

Things That Drive Us Nuts Have you noticed the use of the reCaptcha feature at EE and other web sites?  It wants you to read and retype something that looks like this.Insanity!  It's not EE's fault - that's just the way reCaptcha works.  But it is …
This article discusses how to create an extensible mechanism for linked drop downs.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
The viewer will learn how to create a basic form using some HTML5 and PHP for later processing. Set up your basic HTML file. Open your form tag and set the method and action attributes.: (CODE) Set up your first few inputs one for the name and …

744 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

11 Experts available now in Live!

Get 1:1 Help Now