Hourly CRON task running more frequently than one hour

Posted by Justin on Server Fault See other posts from Server Fault or by Justin
Published on 2010-05-06T21:20:34Z Indexed on 2010/05/06 21:29 UTC
Read the original article Hit count: 248

Filed under:

linux

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ubuntu

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cron

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wget

I have a cron task that calls a special PHP script via wget. Here is the crontab entry:

0 * * * * wget http://www....

It will work perfect for several days, running on the hour. However, after a few days the cron job will start to be called several times an hour. I have never seen CRON drift like this, so I imagine it can't really be a CRON issue. However, the logs of the script that is called clearly show it running several times an hour.

Server details:

Ubuntu Luci
Apache
MySQL
PHP5
Time is showing correct @ command line
Server is setup to sync with a NTP server

In order for the script to run it must be passed a unique 50-character hash key in the URL, so this script isn't being called from any other source accidentally.

What might cause CRON to drift like this?

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