PHP: execute script 5 minutes after first script is run

Question

I'm making a PHP site, and I would like to have a script (when you click a button) which adds some info to my MySQL database (I can do this part by myself) and it executes a script 5 minutes later. Maybe it's not difficult, but it's hard to google stuff like this.

Answer 1

Sleep is a VERY bad idea. Client browser would have to wait 5 minutes to finish request!!!

In my opinion it's not possible to do it like you want to.

You should create another script which queries database and checks if there is new data (and on successful fetch does the job). This script should be run by cron every N minutes.

Answer 2

Pretty tough one. I'd go for something like this:

1. your original script adds a record to the database, containing its time of execution,
2. another script contains the action that needs to be taken 5 minutes later - but launches it only if the db record mentioned above contains a timestamp of at least 5 minues ago (hope that's clear enough, I'm having trouble phrasing this)
3. set crontab to execute the second script every X minutes (perhaps 2).

It won't be 5 minutes EXACTLY, but rather something between 5 and 7 (in case you choose to launch the script every 2 minutes). Would that do?

Answer 3

You could implement a queue in your database, where you add "commands" to be executed, and also store when to execute this command. Then have a cron job that runs every minute and checks said queue to see if it's time to execute a certain command.