[wp-trac] [WordPress Trac] #42866: WordPress Community Scheduler Interval Bug

[WordPress Trac]

#42866: WordPress Community Scheduler Interval Bug
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 Reporter:  mrperl          |      Owner:
     Type:  defect (bug)    |     Status:  new
 Priority:  normal          |  Milestone:  Awaiting Review
Component:  Cron API        |    Version:  4.4.2
 Severity:  normal          |   Keywords:
  Focuses:  administration  |
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 When scheduling tasks using the WordPress API at 15 minute (900 seconds)
 intervals, tasks often run early by about 30 seconds.

 This shouldn't happen, and indicates a bug in the task scheduler that's
 fairly serious. Late I would understand, but early doesn't make any sense.

 Below is a log fragment showing several entries so you can calculate the
 times. Each event should be 900 or more seconds apart, yet several are
 830'ish.

 Here is the source code:
 https://github.com/jamesbriggs/rackping-wordpress-
 widget/blob/master/rackping/rackping.php

 Thanks, James.

 [2017-12-11 04:08:01 UTC] update ok
 [2017-12-11 04:22:17 UTC] Files are less than 900 seconds old, returning.
 [2017-12-11 04:38:01 UTC] update ok
 [2017-12-11 04:52:18 UTC] Files are less than 900 seconds old, returning.
 [2017-12-11 05:08:02 UTC] update ok
 [2017-12-11 05:22:33 UTC] Files are less than 900 seconds old, returning.
 [2017-12-11 05:38:01 UTC] update ok
 [2017-12-11 05:53:02 UTC] update ok
 [2017-12-11 06:08:01 UTC] Files are less than 900 seconds old, returning.

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Ticket URL: <https://core.trac.wordpress.org/ticket/42866>
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