Comments on: Experiments with WP Cron

By: WordPress: WP-Cron and Basic Authentication

WordPress: WP-Cron and Basic Authentication — Thu, 30 Jun 2011 10:19:11 +0000

[...] if maybe wp-cron is broken.I did a some googling and find and interesting article about wp-cron. Experiments with WP Cron explains how wp-cron works and is excellent reading if you find yourself thinking wp-cron is just [...]

By: Brent Shepherd

Brent Shepherd — Mon, 07 Sep 2009 16:29:26 +0000

Simon, in case you ever run across the problem I mentioned above, here is the trac ticket and explanation:

http://core.trac.wordpress.org/ticket/10468

Should be fixed in 2.9 though.

By: Brent Shepherd

Brent Shepherd — Sun, 06 Sep 2009 00:05:53 +0000

Hi Simon,

Yep functions look right now.

Experimenting with wp cron myself, it looks like the function hooked to the schedule item doesn’t receive the full ‘arg’ array. It receives the first value in the array, but not the rest and no array keys (if an associative array).

Did you find this also?

I also tested it with your plugin’s code to make sure and it was reproducible.

Feel free to ignore this, I’ll probably email the wp-hackers list about it too.

By: simonwheatley

simonwheatley — Fri, 04 Sep 2009 19:07:09 +0000

Hi Brent, good spot re the functions.. I think I’ve got it right now?

By: Brent Shepherd

Brent Shepherd — Fri, 04 Sep 2009 18:35:10 +0000

Very handy tutorial, thanks! The codex is a little lite on the general useage of wp-cron.

Just one mixup though, the functions are in reverse order in this sentence:
“To set a one off event, you use the function wp_schedule_event and to schedule recurring events you use wp_schedule_single_event.”

Thanks again.

By: Dennis

Dennis — Sat, 11 Jul 2009 15:09:09 +0000

Oh, I forgot to include that line. But that line is present, like the following:

add_action(“sp_add_post_event”, “sp_add_post”);

I found out that there is a problem with wp-cron. wp_reschedule_event() reschedules event on a proper date in future, but after I reload any page of blog an event is being REMOVED from cron array, and I have no idea why??

By: simonwheatley

simonwheatley — Fri, 10 Jul 2009 11:46:46 +0000

Good point, jarl. Thanks for chipping in!

By: jarl

jarl — Thu, 09 Jul 2009 23:09:32 +0000

To dennis:
You need to add :

add_action(“sp_add_post_event”,”theFunctionYouNeedDone”);

By: simonwheatley

simonwheatley — Mon, 06 Jul 2009 17:51:50 +0000

You could setup something on a cron job that pinged your site’s homepage every however many minutes; you could also use one of the free site uptime monitors and then you also get uptime monitoring!

By: Dennis

Dennis — Sat, 04 Jul 2009 11:44:28 +0000

Got it! WP Cron is actually a pseudo cron, which relies on visitors traffic, so if you don’t have enough traffic cron schedule will not be performed in time. I wonder if it’s possible to set real Cronjob on Unix/Linux server to execute WP Pseudo Cron in WordPress on hourly basis, so that performance doesn’t depend on visitors?