Nginx giving 502 Bad Gateway in random intervals

[d3f3kt]

Oh sorry, that was my fault. I thought you are using php-fpm.
If you are using fcgi than you could use 
/usr/bin/spawn-fcgi -a 127.0.0.1 -p 9000 -u www-data -g www-data -f
/usr/bin/php5-cgi -P /var/run/fastcgi-php.pid -C 6
The number after -C is the amount of children.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,239181,239193#msg-239193