PHP dead pages with php-fpm and nginx

[TECK]

Hi all,

I noticed today some weird errors when I tried to refresh a basic php
page (phpinfo() function).
The page loads fine when I click refresh several times, then all of the
sudden I get a dead page, no 404, no Nginx error, nothing. It looks like
someone disconnected the network cable for a fraction of second. I
checked both php and nginx logs, nothing is there. I even enabled the
debug mode to be safe.

I have a very basic configuration:

	upstream fastcgi {
		server			192.168.0.2:9000;
		server			192.168.0.3:9000 weight=5;
		server			192.168.0.10:9000 weight=5;
	}

	location / {
		try_files		$uri $uri/ /index.php;
	}

	location ~ \.php$ {
		fastcgi_pass		fastcgi;
		include			fastcgi.conf;
	}

Do you know what could generate this issue? The site is closed now so
only 2-3 people have access to the setup.
Do you recommend any tools or settings that will allow me to verify if
the network is shaky?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,193878,193878#msg-193878