WordCamp Baltimore 2015 Presentation for offloading time-consuming, and blocking tasks that slow down WordPress.

1. Aaron Brazell • @technosailor • www.technosailor.com
A S Y N C H R O N O U S
W O R D P R E S S
O F F L O A D I N G H O O K E D E V E N T S TO I N C R E A S E PA G E S P E E D

2. Aaron Brazell • @technosailor • www.technosailor.com
T H E P R O B L E M
( D R A M AT I C T H E M E M U S I C )

3. Aaron Brazell • @technosailor • www.technosailor.com
• Every Time WordPress loads a page, events are fired.
• Plugins typically hook events into init, admin_init,
plugins_loaded, or save_post to fire events
• Every event takes time to complete
• Many dozens of events, all waiting to finish running,
add overhead to WordPress.

4. Aaron Brazell • @technosailor • www.technosailor.com
P O S S I B L E S C E N A R I O S
( S I D E WAY S G L A N C E )

5. Aaron Brazell • @technosailor • www.technosailor.com
E X T E R N A L A P I R E Q U E S T
• Every page load, a site is expected to send a request
to an external API to get the most up to date
information.
• The natural place to make this event happen is on the
init hook.
• The third party API is extremely slow or maybe down
and WordPress must wait up to 30 seconds for the
failure to become known before moving on to the next
event.

6. Aaron Brazell • @technosailor • www.technosailor.com
S AV I N G A P O S T
• Saving posts is potentially one of the most expensive
hooks in WordPress
• There are different kinds of saves: Autosaves. Ajax
events. Non-content saves (Think attachments)
• Actions fire in chronological order. There is no limit to
the number of events that can fire on a hook.
• Virtually any plugin action requiring a “state” update -
meta, API requests, etc - fire on save_post.

7. - S O M E O N E W H O B A D LY M A N G L E D T H E Q U O T E
“Asynchronous Events are not the heroes we
want; they are the heroes we need.”
Photo Credit: V Threepio, via Flickr, Creative Commons

8. T E C H C R U N C H
A S Y N C L I B R A RY
• TechCrunch had extremely
long process times,
particularly with their
CrunchBase API.
• API calls were required to
repopulate cached results.
• Eric Mann (@ericmann) and
John Bloch (@johnpbloch)
built a library to offload tasks
to asynchronous equivalents
• Runs on `shutdown` hook
Photo Credit: Charlyn Wee, via Flickr Creative Commons

9. Aaron Brazell • @technosailor • www.technosailor.com
S T E P S TO I M P L E M E N T
• Install the WP_Async_Task class as a self-contained plugin or
bundle with plugin or theme as separate class. It will only ever be
included one time regardless.
• Create a subclass that extends WP_Async_Task for each hook
that needs to be fired asynchronously.
• Each subclass must contain two methods and a protected
variable $action - prepare_data() and run_action(). The
$action variable must be the name of the hook you’re providing
an alternative for. e.g protected $action = ‘save_post’;
• Hook asynchronous event into wp_async_{action} (e.g.
wp_async_save_post) and pass identical parameters.

10. Aaron Brazell • @technosailor • www.technosailor.com
E X T E N D I N G T H E
P R E PA R E _ D ATA ( ) M E T H O D

11. Aaron Brazell • @technosailor • www.technosailor.com
E X T E N D I N G T H E
P R E PA R E _ D ATA ( ) M E T H O D
• Method runs first. Receives a numerical array passed via
func_get_args(). PROTIP: For insight, print_r()
this array to your error log.
• Modify, sanitize and assign scalar values to a return
array that includes the arguments expected for the hook
you’re implementing. (e.g. save_post takes $post_id
and $post, so this method should set these up). Returns
an associative array with the expected parameters.
• For example, on save_post, return array( ‘post_id’
=> $post_id, ‘post’ => $post_object );

12. Aaron Brazell • @technosailor • www.technosailor.com
E X T E N D I N G T H E
R U N _ A C T I O N ( ) M E T H O D

13. Aaron Brazell • @technosailor • www.technosailor.com
E X T E N D I N G T H E R U N _ A C T I O N ( )
M E T H O D
• Think of this method as the method that actually runs
the processes the formulate the alternative hook.
• Receives the associative array created by the
prepare_data() method as a global $_POST array.
• Be sure to include wp_async_$this->action as:
do_action( ‘wp_async_’ . $this->action,
$variable1, $variable 2); to match the
definition of the core WordPress hook.

14. Aaron Brazell • @technosailor • www.technosailor.com
D E M O N S T R AT I O N

15. Aaron Brazell • @technosailor • www.technosailor.com
R E F E R E N C E S
• TechCrunch Open Sources its WordPress Async Task Library:
http://techcrunch.com/2014/07/31/wp-async-task-our-new-
open-source-library/
• Asynchronous WordPress, by 10up: http://techcrunch.com/
2014/07/31/wp-async-task-our-new-open-source-library/
• Github: https://github.com/techcrunch/wp-async-task/
• Demo Plugin: https://github.com/technosailor/wcbalt-async-wp
• This Presentation: http://www.slideshare.net/technosailor/
asynchronous-wordpress

16. Aaron Brazell • @technosailor • www.technosailor.com
A A R O N B R A Z E L L
• Sr. Web Engineer, 10up
• We’re Hiring Project Managers, WordPress/PHP Engineers
and Front End UX Engineers (http://is10uphiring.com/)
• Twitter: http://technosailor.com/twitter
• Email: aaron.brazell@10up.com
• Github: https://github.com/technosailor
• WP.org Profile: https://profiles.wordpress.org/technosailor

17. Aaron Brazell • @technosailor • www.technosailor.com