High CPU load running php processes

Question

I have dedicate server with 3.1GHz single quad core CPU with 32 GB RAM. It works as a web server and configured to: Apache 2.4 + MPM Worker + Mod_fcgid

When I run top command, I see high CPU usage by PHP processes of website. Below is a snapshot

Tasks: 193 total,   1 running, 112 sleeping,   1 stopped,  79 zombie
Cpu(s): 84.0%us,  1.4%sy,  0.0%ni, 12.3%id,  2.3%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  33554432k total, 26637508k used,  6916924k free,        0k buffers
Swap:        0k total,        0k used,        0k free, 10471152k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                               
 8415 mysql     20   0 12.5g 4.1g 6348 S 115.1 12.8   5107:00 mysqld                                                                                                                
18687 domainus  20   0  303m 110m  44m S 64.5  0.3   1:05.51 php                                                                                                                    
18728 domainus  20   0  311m 118m  46m S 42.7  0.4   1:00.57 php                                                                                                                    
18732 domainus  20   0  333m 140m  45m S 40.3  0.4   1:19.61 php                                                                                                                    
17371 domainus  20   0  306m 114m  46m S 32.5  0.3   0:57.16 php                                                                                                                    
18726 domainus  20   0  278m  87m  47m S 24.8  0.3   1:48.62 php                                                                                                                    
14765 domainus  20   0  324m 133m  47m S 17.7  0.4   4:00.94 php

I want to be sure that, my Apache configuration is right and the problem is with the PHP code, any suggestions on how to drill down the issue?

score 1 · Answer 1 · answered May 12 '15 at 06:50

1

My suggestion would be to run the PHP from the command line and see what happens. If possible turn off Apache beforehand. Also try running the same site/PHP on a different server. If you have no other server available you can use a Vagrant box. One can easily create a box with PHP and Apache using Puphpet.

If no problems arise while running these tests try disabling PHP in Apache and request some plain HTML pages.

answered May 12 '15 at 06:50

Maarten Bicknese

1,498
1
14
27

Maarten, I have wordpress site, any help on how to run from CLI to call any specific page? – maqsimum May 12 '15 at 08:09
How about [Wordpress' unit testing](https://make.wordpress.org/core/handbook/automated-testing/)? – Maarten Bicknese May 12 '15 at 08:22

score 1 · Answer 2 · answered May 12 '15 at 07:54

I think the bottleneck here is your MySQL as its consuming most of cpu and php most probability is making those querying. The issue could be due to poor php code.

Correct way to drill down the problem so make use of php profiler and see which function is taking time and then dealing with appropriately. Like db interaction is taking time then try to cache queries, batch queries to avoid concurrency issues.

High CPU load running php processes

2 Answers2