WC_Payments_Action_Scheduler_Service::schedule_job() is causing slow downs

[prettyboymp]

The WC_Payments_Action_Scheduler_Service::schedule_job() can get called dozens of times during the process of creating an order. Each time the callback is hit, calling as_unschedule_action() is adding quite a bit of overhead. This handling was added in #1295.

woocommerce-payments/includes/class-wc-payments-action-scheduler-service.php

Lines 147 to 153 in db6e444

	public function schedule_job( int $timestamp, string $hook, array $args = [], string $group = self::GROUP_ID ) {
	// Unschedule any previously scheduled instances of this particular job.
	as_unschedule_action( $hook, $args, $group );
	// Schedule the job.
	as_schedule_single_action( $timestamp, $hook, $args, $group );
	}

Do we need to unschedule and reschedule the job, or can we simply call as_has_scheduled_action() instead?

as_has_scheduled_action() doesn't require that the query for the scheduled action be ordered by the date, so it doesn't have the same query issues with requiring a filesort that the normal query to get the next action does.

cc @dmallory42

[htdat]

Thanks for the report. We have prioritized it. In case, you need to fix this soon, let us know.

It seems related to this issue #5279 by @marcinbot

[zmaglica]

I will close this issue in favor of this issue: #5279