high "Load Average"

[Sessna]

Cliff Wells Wrote:
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> You fail to mention what sort of disk subsystem you are using.   
One SCSI disk

> High load is often indicative of I/O bottlenecks.   
> You also don't mention what OS you are using, 
CentOS release 5.4

> you should install iotop and take a look at what process is driving the load
Here is the snippet from iotop output
Total DISK READ: 3.33 K/s | Total DISK WRITE: 3.27 M/s
  TID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND
20264 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp
21604 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp
21605 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp
20054 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp
20902 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp
20275 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp
20828 be/4 nobody      0.00 B/s    0.00 B/s  0.00 % 99.99 % php-cgi --fpm --fpm-config /etc/php-fp

Looks like php-cgi makes 99.99% IO, but not really sure what this means

> (it might be Nginx, but more likely MySQL - restarting Nginx simply cancels whatever pending
> requests MySQL had is my guess).
MySQL is running on another PC, so php makes network connections to DB. It may take a while, of course, but should not php being blocked and sleeping while network system is processing request?

Thanks,
Sessna

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,63176,63324#msg-63324