Hello fellow programmers! :)
I want to be able to set up some php script to be run after some events, triggered by user. Let's say, user creates a forum thread, that should be closed after 48 hours automatically. It is equivalent to an update to MySQL row: UPDATE threads SET closed = '1' WHERE threads.id = 'x'. Hence, this problem should not necessarily be solved exclusively with php.
This kind of questions pop up from time to time, but everything I found was to set up a cron job to run every 'x' amount of time, that checks if the time has come to close the thread. The problem is, that running this checks often cause higher system load than if you schedule a script to be run once at a given time. Not to forget, that there could be hundreds or even thousands of threads, each with it's own time to be closed. We can avoid checking every single thread by creating some sort of queue, for instance in MySQL, so the script selects from the DB entries with "time_to_close < NOW()" and closes these. Another drawback is, that I would like the thread to be closed exactly after 48 hours. In that case the script should be run every second and should take very little time to be executed completely.
Alternatively to cron job I think following method can also be useful: check at every access to the Thread if it should be closed. This also causes higher load, especially if the thread is accessed very often.
So is there any efficient way to schedule a (php) script run depending on the time of a specific event? While writing this question I stumbled upon MySQL event scheduler. Together with procedures, that can provide additional flow control (close thread only if there was no activity since 48 hours) I think my idea can be implemented. I am not familiar with these functions of MySQL, so I would appreciate any help on this topic.
With best regards, system__failure.
