Support » Fixing WordPress » High CPU Load After Update to v4.3

  • Resolved Tranny


    I run a busy high traffic and high community participation site, so MySQL has always run very high on my server. But after upgrading to v4.3 (no other change), my CPU load tripled, and it’s crippling the server, causing frequent crashes and generally degraded responsiveness.

    The site is hosted on a high end dedicated server with 4 SSD drive in hardware RAID. I spoke with my host and they assured me no changes have been done to the server, and all server side applications are up to date.

    Problems started after the update to v4.3, No other change whatsoever has been done to neither the WP installation, nor the server itself.

    My log shows high http connection count, which use abnormally high CPU never seen before:

    17368 mysql 20 0 9348m 441m 6852 S 42.0 1.8 8:35.43 mysqld
    17941 xxxxx 20 0 1474m 54m 4748 S 27.5 0.2 0:10.38 httpd
    18526 xxxxx 20 0 1463m 43m 4680 S 27.1 0.2 0:01.42 httpd
    16675 xxxxx 20 0 1467m 46m 4284 S 24.8 0.2 0:17.30 httpd
    16830 xxxxx 20 0 1463m 42m 4300 S 23.5 0.2 0:16.92 httpd
    17777 xxxxx 20 0 1454m 34m 4780 S 23.5 0.1 0:11.56 httpd
    18358 xxxxx 20 0 1460m 40m 4760 S 23.5 0.2 0:04.49 httpd
    17881 xxxxx 20 0 1460m 40m 4716 S 23.2 0.2 0:09.88 httpd
    18220 xxxxx 20 0 1441m 21m 4768 S 23.2 0.1 0:05.12 httpd
    18472 xxxxx 20 0 1460m 40m 4748 S 23.2 0.2 0:04.12 httpd
    18331 xxxxx 20 0 1505m 84m 4700 S 22.5 0.4 0:04.02 httpd
    16892 xxxxx 20 0 1463m 43m 4316 S 22.2 0.2 0:09.67 httpd
    16872 xxxxx 20 0 1441m 20m 4240 S 17.9 0.1 0:21.70 httpd
    18248 xxxxx 20 0 1446m 26m 4756 S 16.9 0.1 0:03.51 httpd
    16479 xxxxx 20 0 1461m 41m 4688 S 16.2 0.2 0:19.24 httpd
    16870 xxxxx 20 0 1458m 37m 4216 S 16.2 0.2 0:16.59 httpd
    18452 xxxxx 20 0 1474m 54m 4652 R 14.2 0.2 0:01.97 httpd
    16729 xxxxx 20 0 1461m 40m 4208 S 12.2 0.2 0:18.65 httpd
    16978 xxxxx 20 0 1455m 35m 4248 S 9.3 0.1 0:11.55 httpd

    Can anyone help me out with this? What happened? This is the first time I see my server getting crippled after a WP update and I’ve run this particular site on WP since 2008.

Viewing 15 replies - 1 through 15 (of 96 total)
  • I have the exact same problem!

    i am having the same issue too i have upgraded to 4.3 and my high busy web site is getting high cpu usage it is been a long time since these problems…

    please advice what you are going to do

    Moderator Samuel Wood (Otto)

    (@otto42) Admin

    4.3 isn’t really a big update that would cause this sort of thing. Have you examined your error log and access logs to see if anything is out of the ordinary?

    hi samuel can you help me i am in a really bad situation here.

    Thread Starter Tranny


    Is there a way to revert back to the previous version without losing new DB records? Something is definitely not right with this latest release.

    I do have DB backups, but there’s been a lot of activity in the last 2 days since I updated WP, as I get on average one new comment every 2 minutes.

    There were changes to the DB structure in the latest release, so I can’t just overwrite the files with the old ones. What can I do to revert to the previous version?

    Me too, my cpu is high since this morning and I disabled all my plugins and changed my theme by default, it fixes nothing. Please help…

    Moderator Samuel Wood (Otto)

    (@otto42) Admin

    WordPress is ultimately just a PHP script. It can’t cause this sort of thing. PHP has a timeout for long running scripts.

    Are you guys all on the same host or something? Did anything else change?

    Moderator Samuel Wood (Otto)

    (@otto42) Admin

    Is there a way to revert back to the previous version without losing new DB records?

    No, definitely not. 4.3 did work with the terms system that is not safe to downgrade with. If you want to downgrade, you need to restore from backups, completely.

    My host is ovh, french dedicated server and this problem arrived this morning without touching anything

    Thread Starter Tranny


    I’m on a reliable dedicated server, as I had mentioned earlier. One other person who commented here is also on a dedi.

    I also use CloudFlare Pro, and contacted their tech to verify and make sure the traffic is still properly filtered through their CDN and content is served from their caches. There’s no change there.

    Perhaps it would be a different matter if didn’t so obviously start after update to v4.3 with no other change done to the set up. This has also never happened before, so it’s not an old problem coming back.

    I’m having the same problem where I can’t even get to my Dashboard Admin pages unless I keep monkeying around disabling plugins to get the Admin side to work. The client facing side is okay as CloudFlare is dishing out the pages from their cache.

    Currently I can’t get into my Dashboard.

    Hopefully a 4.3.1 update can get pushed out to resolve these problems.

    same here, dedicated server, Cloudflare Pro, the is running twice as slow after the last update, crashing randomly throughout the day

    Moderator Samuel Wood (Otto)

    (@otto42) Admin

    Here is the ticket about this issue:

    Cleaning out the cron entry in the database will stop the madness.

Viewing 15 replies - 1 through 15 (of 96 total)
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