Lots of CLOSE_WAIT sockets, nginx+php (WordPress site)

[Maxim Dounin]

Hello!

On Mon, Feb 22, 2010 at 12:20:26PM +0100, Vicente Aguilar wrote:

> Hi
> 
> >>        fastcgi_ignore_client_abort on;
> >>        fastcgi_connect_timeout 60;
> >>        fastcgi_send_timeout 180;
> >>        fastcgi_read_timeout 180;
> > You are ignoring client aborts, and has relatively large timeouts 
> > set for fastcgi.  Are you sure the connections in question aren't 
> > disappear as soon as your fastcgi backend finishes preparing 
> > response?  I.e. check if any particular connection stay for at 
> > least 5 minutes or so.
> > 
> > Additionally, check if you are able to reproduce the problem with 
> > fastcgi_ignore_client_abort off.
> 
> That was my current config which I copied from a site discussing php-fpm. My initial fastcgi config was:
> 
>   location ~ .php$ {
>     # By all means use a different server for the fcgi processes if you need
>     # to
> #    fastcgi_pass   unix:/tmp/php-fastcgi.sock;
>     fastcgi_pass   127.0.0.1:9000;
>     fastcgi_index  index.php;
>     fastcgi_param  SCRIPT_FILENAME /var/www/$host/$fastcgi_script_name;
>     include /etc/nginx/fastcgi_params;
>     fastcgi_intercept_errors on;
>   }
> 
> And also had the problem.

Do you also had CLOSE_WAIT sockets which 
fastcgi_ignore_client_abort off?

> > Not responding just because of 100 connections seems strange 
> > for nginx even with worker_connections 1024, so I suspect you 
> > just run out of php processes and CLOSE_WAIT's are because of 
> > fastcgi_ignore_client_abort.
> 
> That's what I think too, but there are no stuck PHP connections 
> in netstat. Whenever a PHP page is loaded I got some nginx-PHP 
> sockets but they all close OK, none gets stuck. Only on the 
> client-nginx end is where I can see this behavior with netstat. 

By "stuck" you mean sockets in CLOSE_WAIT state?  It's expected 
that there is no CLOSE_WAIT sockets between nginx and php.

Maxim Dounin