I have a Wordpress Network that I am tasked with disabling the WP Cron and replacing it with an Apache Cron. I have set up a PHP script that when called by an Apache Cron will loop through all sites under the network and make a request to that site's wp-cron.php page, thus executing its cron.
I would like to use Wordpress' transient feature to limit my PHP script as Wordpress limits its own cron. However, when I dig into the code I see the doing_cron transient is set ( in cron.php #217 ) but never unset.
Is the transient ever unset or does Wordpress wait 60 seconds to fire up the cron again ( in cron.php #200 )
Any thoughts on the doing_cron transient or perhaps another means to throttle my cron script would be appreciated.