Showing posts with label cron. Show all posts
Showing posts with label cron. Show all posts

Thursday, August 21, 2008

Cron entry mistakes

This mistake came at the expense of one of my old co-workers, who decided to share this with me over Instant Messenger. I got a good laugh at his misfortune. He wanted to set up a cron job that would restart a poorly performing service every 6 hours. This is the cron entry he added.

* */6 * * * service_restart.sh

The lead developer, whose app depends on that service, came up to him wondering why his app was having outages. What my colleague should have configured was

0 */6 * * * service_restart.sh

His cron entry was restarting the service every 6 hours, and then restarting it every minute for an hour during that sixth hour. Brilliant! Although I guess I shouldn't throw stones in glass houses.