Nginx + PHP = VERY High CPU Usage

[hasson]

Hello All,

I was using APACHE and I decided to migrate to nginx.
I researched and nginx is supposed to have a completely superior
performance for webpages that have lot of simultaneous requests, such as
real time pages sending AJAX requests every second.

My application is based on MYSQL + PHP + AJAX + JAVASCRIPT.

After I installed the NGINX, I started testing it, and noticed that
something is strange due the HIGH-CPU usage of PHP-CGI process.

The curious is that with around 6-8 Tabs open on Firefox, I can reach
around 80% of CPU usage. that is completely high, even with this test
machine that have a cpu of only 1.8ghz. But talking about only 8 web
pages open, reach this amount of CPU usage, I think that something is
wrong.

Anyone can please advise me?

[size=x-small]last pid: 39019;  load averages:  0.98,  0.22,  0.08      
                                                                      
up 4+16:53:45  17:03:29
51 processes:  2 running, 49 sleeping
CPU: 84.8% user,  0.0% nice, 14.4% system,  0.4% interrupt,  0.4% idle
Mem: 46M Active, 204M Inact, 83M Wired, 128K Cache, 60M Buf, 157M Free
Swap: 991M Total, 991M Free

  PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
39017 www         1  70    0 18908K 10932K accept   0:04 17.09% php-cgi
39009 www         1  72    0 18908K 11396K accept   0:05 16.26% php-cgi
39008 www         1  68    0 18908K 11428K accept   0:05 15.67% php-cgi
39019 www         1  66    0 18908K 10932K accept   0:03 15.48% php-cgi
39018 www         1  64    0 21980K 13100K RUN      0:03 13.96% php-cgi
  954 mysql      14  44    0 63332K 30672K sbwait   5:55  0.00% mysqld
 1150 daemon      6  44    0 13460K  6716K ucond    0:34  0.00%
memcached
 1617 nobody      1  44    0  5348K  4180K kqread   0:12  0.00% nginx
 1009 root        1  44    0  6080K  3476K select   0:11  0.00%
sendmail
 1020 root        1  44    0  3376K  1372K nanslp   0:04  0.00% cron
 1001 root        1  44    0  6704K  3744K select   0:02  0.00% sshd
  642 root        1  44    0  3348K  1336K select   0:02  0.00% syslogd
38189 rafael      1  44    0  9428K  4552K select   0:01  0.00% sshd
 1013 smmsp       1  44    0  6080K  3332K pause    0:00  0.00%
sendmail
  783 www         1  73    0 17884K  8412K wait     0:00  0.00% php-cgi
  812 nobody      1  44    0  3292K  1296K select   0:00  0.00% noip2
38186 root        1  44    0  9428K  4488K sbwait   0:00  0.00% sshd
 1487 root        1  44    0  5348K  3636K pause    0:00  0.00% nginx
38193 root        1  44    0  4564K  2404K wait     0:00  0.00% bash
39016 root        1  44    0  3684K  1956K RUN      0:00  0.00% top
  823 root        1  76    0  3628K  1504K wait     0:00  0.00% sh
38192 rafael      1  44    0  3808K  1724K wait     0:00  0.00% su
38190 rafael      1  45    0  3628K  1612K wait     0:00  0.00% sh
 1084 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
  508 root        1  44    0  1888K   584K select   0:00  0.00% devd
 1086 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
 1085 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
 1089 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
 1087 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
 1090 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
 1091 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
 1088 root        1  76    0  3348K  1156K ttyin    0:00  0.00% getty
  120 root        1  76    0  1540K   844K pause    0:00  0.00%
adjkerntz[/size]

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,157575,157575#msg-157575