Support » Fixing WordPress » Self-starting processes result in 99 +% CPU usage

  • Hello,

    I have a big problem which I and the hostingcompagnie can’t fix.
    Can anyone be so kind to help/advise?

    The problem:
    We run a Woocommerce webshop.
    We got the 503-507-508 errors al lot on Monday and Tuesday.
    The hosting company says that there a processes that ask to much of their servers and that keep going en not stop, they loop.
    In the ‘resource usage details’ panel (, it looks like it started on Wednesday the 9th of October, but we had no problems until Friday the 28th of October.
    I have installed Putty and see the following:
    There are processes using 99+% of the CPU. ( They run for hours/days. When we kill them with Putty they will just restart again.

    Active WordPress plugins right now: (we need them to run te shop)
    C4D Plugin Manager
    C4D Woo Variation Images
    Conditional Payments for WooCommerce
    Conditional Shipping for WooCommerce
    Electro Extensions
    Redux Framework
    WC Hide Shipping Methods
    Woo Custom Stock Status
    WooCommerce Advanced Free Shipping
    WooCommerce Min Max Quantity & Step Control Single
    Woocommerce Payment Methods
    WooCommerce Product Tabs
    WOOF – WooCommerce Products Filter
    WP Crontrol
    WP Super Cache
    YITH WooCommerce Ajax Product Filter
    YITH WooCommerce Product Add-ons
    Plus a lot of inactive plugins right now to test. But with these activated in the past, there were no problems.

    We have 1 theme installed with it’s child theme and the Twenty Sixteen theme inactive.

    In WordPress -> WP-Cron Events, I deleted all events, the line in putty too.
    So all the lines with the high CPU were gone. Only the 4 standard ones were running at 0% – 0,3% CPU. (
    After a couple of minutes the first high CPU usage line came back again.
    And later more and more came up again.
    The left over cron jobs I can not delete, but have set to recurrence one a day.

    We have 2 advertisements on Google Ads. I paused them, killed the high usage lines in putty. But these line came back again after.

    So I do not know what to do next…
    Can anyone be so kind to help/advise?

Viewing 7 replies - 1 through 7 (of 7 total)
  • My first thoughts are PHP 7.X if you’re still on 5.6.X…

    Sounds to me like you need to buy some more horsepower…

    If I was running an online store I’d be tickled to see it busy and, as long as there was a business case for it, I’d be spending my money on more horsepower.

    You might start by splitting your hosting and database duties to separate servers.

    A CDN might be a very good idea and then run a very good cache plugin.

    Once you get a handle on the 500 errors you might want to run Cloudflare in front of your site.

    • This reply was modified 2 years, 8 months ago by JNashHawkins.


    I suggest running a malware check…those processes could be doing bitcoin mining.

    Malware check is a good idea but I’d have expected the host to have tried that already.

    If they’d of included a domain name I’d have looked deeper and ran it myself for them via Sucuri!

    Also, sometimes when killing the scheduled task via the Crontrol plugin you’ll get a spike as some plugins bring on a dearth of tasks to play ‘catchup’.

    Another idea would be to trigger cron manually instead of letting the pseudocron deal with that.

    I’d go with more horsepower or splitting the load across two servers. I always lean toward two or more servers. Horsepower and servers are cheap.

    • This reply was modified 2 years, 8 months ago by JNashHawkins.

    Sharing the domain name would be helpful. Have you checked the crons on the server when logged into SSH?

    crontab -u u48172p4 -l

    If that doesn’t reveal anything then you can use strace -p PID# and lsof -p PID# – these will give you a lot of “noise” but if you go through it then you should be able to find the cause of index.php going rogue like that.

    Did you install or update any themes or plugins before the CPU spike happened?

    Try checking your traffics to see if they are legitimate. You may be under some bot attacks. Placing your website behind CloudFlare should help in this case.

    Thread Starter SLV


    Thanks for helping, much appreciated!

    It took me some days but I found the cause of this problem.
    It was the YITH WooCommerce Ajax Product Filter plugin.
    The hosting company said that there were processes that ask to much of their servers and that keep going en not stop, they restart themselves when killed.
    So when customers select filters to search for products and leave the site, dat process is still in processes, it doesn’t stop when the customer leaves. If we kill this proces in Putty, it comes right back up. The CPU had too much processes of 99+% to work through and the sites stops working.
    So I have deactivated that plugin and the problem is solved.

Viewing 7 replies - 1 through 7 (of 7 total)
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