Running a PHP script every 5 minutes and avoiding race conditions

Question

I have a php script that needs to run once every 5 minutes. Currently I\'m using a cron job to run it (and it works great) but my host only allows a minimum time of 15 minut

Answer 1

Lame answer for a lame situation (the ISP, not the poster). Schedule 12 cron jobs, all calling the same script, each running once per hour, but calling at a different 5 minute mark.

00 * * * * root echo "run at :00 of every hour"
05 * * * * root echo "run at :05 of every hour"
10 * * * * root echo "run at :10 of every hour"

etc until :55. But I stand by my original comment - find a new ISP :)