Apache getting hammered... Wordpress site. CPU 100%

January 30, 2015 15.6k views
varange
By:
varange

Hi folks. I hope one of your gurus can point me in the right direction.

I have two servers, one for Apache and one for MySQL, 4GB and 2GB RAM respectively. They run about 10 wordpress sites with very low traffic, and resources have not been a problem.

I now added another WP site with about 3000 pageviews per day and the server that runs Apache is sitting at 100% CPU all the time. Page load speed is dismal, somewhere around 6 seconds.

The site is www.fairtattoo.com. It has about 5000 posts currently.

Plugins are W3Total Cache, SEO by Yoast, WP Optimize. The theme is a professional theme from mythemeshop (truepixel) and I have used it without a problem on other sites.

Apache uses mpm_prefork.

Strangely, apache will use only about half the available RAM, approx 2GB of teh 4GB available. I've tried tweaking mpm_prefork with a few variations, but no luck so far.

Here's the mpm_prefork:

<IfModule mpm_prefork_module>
    # Default 5
    StartServers        5

    # Default 5
    MinSpareServers     5

    # Default 10
    MaxSpareServers     10

    # default 256
    ServerLimit     256

    # default 256, less or same as Server Limit
    MaxRequestWorkers   256

    # deprecated: Called MaxRequestWorkers now
    #MaxClients     128

    # Can be a high number like 20000 but do not set to 0 (unlimited)
    MaxConnectionsPerChild  20000

    # No need to Keep alive, just keeps threads busy
    KeepAlive On

Where next? How to diagnose?

Thanks in advance

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4 Answers
varange January 30, 2015 
top - 11:58:29 up 11:36,  1 user,  load average: 27.45, 30.32, 38.95
Tasks: 131 total,  19 running, 111 sleeping,   0 stopped,   1 zombie
%Cpu0  : 96.7 us,  2.7 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.7 hi,  0.0 si,  0.0 st
%Cpu1  : 97.3 us,  2.7 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem:   4048356 total,  1665908 used,  2382448 free,   123444 buffers
KiB Swap:  3906244 total,       80 used,  3906164 free.   645800 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                  
30513 www-data  20   0  452972  48640  28352 S  11.3  1.2   0:01.58 apache2                                                  
30512 www-data  20   0  450304  45668  27912 S  11.0  1.1   0:03.54 apache2                                                  
30633 www-data  20   0  450580  43536  25520 R  11.0  1.1   0:01.45 apache2                                                  
30570 www-data  20   0  452640  44888  25272 R  10.0  1.1   0:04.97 apache2                                                  
30533 www-data  20   0  452896  45084  25204 R   9.3  1.1   0:02.35 apache2                                                  
30553 www-data  20   0  453404  45748  25140 S   9.3  1.1   0:02.26 apache2                                                  
30572 www-data  20   0  453220  48004  27804 R   9.3  1.2   0:01.59 apache2                                                  
30523 www-data  20   0  452960  47456  27484 R   9.0  1.2   0:01.44 apache2                                                  
30571 www-data  20   0  470120  86828  49700 R   9.0  2.1   0:02.14 apache2                                                  
30591 www-data  20   0  450336  42860  25092 R   9.0  1.1   0:03.88 apache2                                                  
30574 www-data  20   0  453152  45588  25224 R   8.6  1.1   0:02.18 apache2                                                  
30632 www-data  20   0  452120  44460  25120 R   8.6  1.1   0:01.02 apache2                                                  
30507 www-data  20   0  457268  53112  28408 R   8.3  1.3   0:05.94 apache2                                                  
30552 www-data  20   0  453164  45592  25224 R   8.3  1.1   0:02.19 apache2                                                  
30515 www-data  20   0  475780 105148  62596 S   7.0  2.6   0:03.52 apache2                                                  
30585 www-data  20   0  452888  45036  25108 S   6.3  1.1   0:01.80 apache2                                                  
30590 www-data  20   0  451864  43912  25096 R   5.3  1.1   0:01.68 apache2                                                  
30560 www-data  20   0  450332  42908  25136 R   5.0  1.1   0:04.42 apache2                                                  
30593 www-data  20   0  452864  45244  25128 R   5.0  1.1   0:01.75 apache2                                                  
30556 www-data  20   0  450336  42996  25220 S   4.3  1.1   0:01.93 apache2                                                  
30589 www-data  20   0  450340  42984  25208 S   4.0  1.1   0:01.89 apache2                                                  
30509 www-data  20   0  454144  49332  27888 S   3.7  1.2   0:02.92 apache2                                                  
30524 www-data  20   0  452888  45164  25140 R   3.3  1.1   0:02.37 apache2                                                  
30562 www-data  20   0  452864  45240  25124 S   2.7  1.1   0:01.87 apache2                                                  
30564 www-data  20   0  450080  42656  25136 R   2.7  1.1   0:02.03 apache2                                                  
30602 www-data  20   0  453144  45496  25136 R   2.7  1.1   0:01.59 apache2                                                  
30545 www-data  20   0  450328  42928  25160 R   2.3  1.1   0:01.60 apache2                                                  
30558 www-data  20   0  452968  46724  26520 S   2.3  1.2   0:02.06 apache2                                                  
30618 www-data  20   0  453148  45488  25152 S   2.3  1.1   0:01.13 apache2                                                  
30554 www-data  20   0  450328  42884  25116 S   1.7  1.1   0:01.52 apache2                                                  
30565 www-data  20   0  450328  42892  25124 S   1.7  1.1   0:02.25 apache2
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varange January 30, 2015

OK, found the problem!

The THEME! Really, no jokes. Who woulda thought?

I load a different theme (twenty-fifteen) and life is good.

Goes to show.

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  • sierracircle January 30, 2015

    I have had certain plugins cause similar problems.

    As a side note: you might consider changing wp-login.php to something different. It is not difficult and prevents a lot of brute-force login attempts, which can also overload apache

varange January 31, 2015

Good thought! I installed Theme-My-Login, and that redirects and puts Recaptchas whereever I want them

https://wordpress.org/plugins/theme-my-login/

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varange January 31, 2015

Also, as a quid pro quo, I thought I'd describe to other readers of this thread how to get Theme-My-Login to disable wp-login.php.

Step 1: Install Theme My Login. Just look for a new plugin from your wordpress admin console
Step 2: Enable the Security Module from TML Settings

http://www.fairtattoo.com/wordpress/wp-content/uploads/2015/01/tml_enable_security.png

Step 3: Go to the Security Module's settings and "Disable wp-login"

http://www.fairtattoo.com/wordpress/wp-content/uploads/2015/01/tml_disable_wp-login.png

That's it!

I also like to set up Recaptcha. Easy enough to do.

PS: Jonathan, would you link to the media files in this comment please? No idea how to do that.

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