[wp-trac] [WordPress Trac] #32306: wp-cron occassionally throws 500 errors for SSL enabled sites

[WordPress Trac]

#32306: wp-cron occassionally throws 500 errors for SSL enabled sites
--------------------------+-----------------------------
 Reporter:  coatesg       |      Owner:
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Cron API      |    Version:  4.2.1
 Severity:  normal        |   Keywords:
  Focuses:                |
--------------------------+-----------------------------
 I have several WP installs that are throwing 500 error codes when calling
 wp-cron.php after a pageview. The error is not consistent - it will
 sometimes return 200, and sometimes 500. All the installs I see this on
 use SSL with properly signed certs with SNI in use on the server under
 Apache. Instances on the same server where do not use SSL have not shown
 this issue at all.

 I have managed to reproduce this on a clean WP install running
 twentyfifteen with no plugins installed so it doesn't appear to be plugin
 related.

 Oddly, I don't get any PHP warnings when it happens (though I've tested
 that if I force a php script in the same pool to throw an error, it does
 get captured) - I do get the following recorded in the Apache Virtualhost
 error log (redacted):

 [Fri May 08 08:29:34.479946 2015] [core:error] [pid 13870:tid
 140644332824320] [client xxxx:xxxx:x:xx:xxxx:xx:x:x:57492] AH00524:
 Handler for fastcgi-script returned invalid result code 32

 Apache access log (redacted):

 xxxx:xxxx:x:xx:xxxx:xx:x:x - - [08/May/2015:08:29:26 +0100] "POST /wp-
 cron.php?doing_wp_cron=1431070166.8151741027832031250000 HTTP/1.0" 500
 4066 "-" "WordPress/4.2.2; https://www.domain.com"


 System config is as follows:

 * Fully patched Debian Jessie running on amd64 arch with kernel 3.16.0
 * Webserver: Apache/2.4.10 (Debian), mod_fastcgi/mod_fastcgi-
 SNAP-0910052141, mod_fcgid/2.3.9, mod_python/3.3.1, Python/2.7.9,
 OpenSSL/1.0.1k
 * MySQL 5.5.43-0+deb7u1
 * PHP 5.6.7+dfsg-1 running under PHP-FPM (seen with and without opcache in
 place)
 * Wordpress 4.2.2 fresh install (also seen on 4.2.1) with all plugins
 removed.

 The server listens both on IPv4 and IPv6 - I've tried forcing wp-cron to
 use IPv4 by setting the hostname in /etc/hosts but that makes no
 difference.

 Refer also to :

 https://wordpress.org/support/topic/wp-cron-throwing-500-errors-on-ssl-
 sites?replies=9

--
Ticket URL: <https://core.trac.wordpress.org/ticket/32306>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform