[wp-trac] [WordPress Trac] #44795: WordPress Heartbeat Interval stuck on 15 secs

[WordPress Trac]

#44795: WordPress Heartbeat Interval stuck on 15 secs
--------------------------+-----------------------------
 Reporter:  Nicksws       |      Owner:  (none)
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  General       |    Version:  4.9.8
 Severity:  normal        |   Keywords:
  Focuses:                |
--------------------------+-----------------------------
 Hi!

 I think I've found a bug with the WordPress Heartbeat API, in short, on
 some installs ( Only some ) I am unable to alter the interval.

 On some of our installs ( we manage 200+ ) we are finding admin-ajax.php
 hitting our servers pretty hard and on occasion will cause a 503 error.

 To try and resolve this ourselves, we have tried:

 - Deactivating all plugins, switched to the twenty fifteen theme.
 - Tried using specific plugins to alter this value ( 3 in total and all
 didn't alter this value ).
 - Tried using the code from the codex - this doesn't correct the issue on
 an affected install.
 - Tried asking WordPress Stack Exchange here:
 https://wordpress.stackexchange.com/questions/311123/unable-to-change-the-
 wordpress-heartbeat-interval-on-some-installs-others-allow
 - Tried the WordPress support forum here:
 https://wordpress.org/support/topic/wordpress-heartbeat-interval-problems-
 stuck-on-15-secs/
 - Tried asking two hosting companies ( Still investigating ).
 - Tried asking Advanced WordPress Facebook group - no luck with anything
 here yet.

 As you can see, we've made significant effort to try and resolve this
 problem on our own without any luck.

 **Function causing the issue**

 Locating where this is coming from, I've tracked it to the heartbeat.js
 file.
 The function is interval on line 612 of the non minified version.

 If I alter the same function in heartbeat.min.js ( Altering 15e3 to 60e3
 ), the interval will now be set to 60 and admin-ajax.php requests drop
 dramatically.

 With all the effort I've put in to fix this and failing, I can only assume
 this is a bug of some kind.

 **Other info**

 - This is not every website we have, on different hosting platforms.
 - Some websites are completely fine, others are not.
 - Doesn't seem to make a difference which browser ( Firefox and Chrome
 tested ).
 - All websites are updated often with the latest core version.

 **Expected Result**

 We expected to be able to adjust to heartbeat interval to a slower rate.

 Hopefully this covers everything needed, please let me know if not!

 Thanks
 Steven

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/44795>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform