CUNY Academic Commons

While looking into the performance issues from our latest maintenance update, I was monitoring Cavalcade and noticed a bunch of new 'action_scheduler_run_queue' tasks. I found that the PDF Embedder plugin added usage tracking to its plugin in their latest update: https://github.com/cuny-academic-commons/cac/commit/851b5a3fd6d8dc7921e56dcba40238ac57a7c17a#diff-6edecdd2d2a0cad82a8d177ed3113d40362970a39adea1240f444e0187c821f9

To do this, the plugin utilizes the Action Scheduler library to schedule a task that sends usage data back to the developer. (Side note: In #17672, I throttled the Action Scheduler task to run every 15 minutes instead of every minute.) Since PDF Embedder is a widely-used plugin (roughly 1700 sites use it), this can somewhat explain the performance issues directly after the maintenance update this week.

Even though usage tracking is opt-in by default, the problem with the developer's implementation is the Action Scheduler library runs all the time even when usage tracking is disabled. I've posted a new topic to the wp.org plugin support forum here: https://wordpress.org/support/topic/limit-action-scheduler-to-only-run-if-usage-tracking-is-enabled/ . Hopefully they can address this soon.

For now, I'm going to look into disabling the Action Scheduler task from the PDF Embedder plugin. Once done, I'll remove all 'action_scheduler_run_queue' Cavalcade tasks related to the PDF Embedder plugin.