使用Cron作业激活PHP脚本但它没有完全运行

Question

I am using cronjob to activate a php script. Although when i do it manually from the browser, the script takes 3-4 seconds to load and it outputs result into the database.

When cron job does it, it seems that the script is unable to complete in the alloted time and the cronjob stops loading the script mid way, the cron works about 1/10 of the time, the rest 9/10 times it fails to complete the task. Is there a way i can ensure that the script is loaded completely each time the cron job activates it?

Script is simple completely php based. Any suggestions?

Answer 1

I'd suggest implementing a lockfile (overrun protection) solution. Basically when your script kicks off it will do a check for a lockfile, and if the lockfile exists, the script can assume the previous incantation is still running, so it will halt execution. And when the script is complete it will remove the lockfile so subsequent runs can get passed the lockfile check and execute in their entirety.

A lock file usually contains the process id spawned by the script and usually located somewhere like /var/lock/my_script.lock.

You can google around for more info, but here is a site with a lockfile example.