We have a webserver with apache 2.2.14, PHP 5.3.2.
PHP is executed using mod_fcgid (see bottom). Everything works fine but sometimes, and we still have to figure out what triggers this, when php processes are "rotated" they remain active and orphaned: apache spawns new php processes and the old ones remains on the system. Killing them doesn't always kicks them away. More likely an "apache2ctl graceful" frees the system from this stale processes. We found this in error log: [Tue Jun 18 20:49:54 2013] [warn] mod_fcgid: process 2009 graceful kill fail, sending SIGKILL from what I found searching around this is quite normal, but that's all I found in apache logs during one of this processes leak.
This event is luckily seldomly happening, usually apache and php operate normally and with no problems during fcgid childrens renewal. How can we understand what's going wrong in these situations?
mod_fcgid config in site:
<IfModule mod_fcgid.c>
SuexecUserGroup domain domain
<Directory /var/www/fomain.it/htdocs/>
AddHandler fcgid-script .php
FCGIWrapper /var/www/fcgi/domain.it/fcgi-starter-php .php
Options +ExecCGI -Indexes
AllowOverride FileInfo Options
Order allow,deny
Allow from all
</Directory>
<Directory /var/www/fcgi/domain.it/>
AllowOverride None
Options +ExecCGI MultiViews -Indexes
Order allow,deny
Allow from all
</Directory>
</IfModule>
/var/www/fcgi/domain.it/fcgi-starter-php:
#!/bin/sh
PHPRC=/var/www/fcgi/domain.it/php/
export PHPRC
PHP_FCGI_CHILDREN=8
export PHP_FCGI_CHILDREN
PHP_FCGI_MAX_REQUESTS=5000
export PHP_FCGI_MAX_REQUESTS
exec /usr/lib/cgi-bin/php $1
We currently found a workaround to avoid the server to fill up with orphaned processes. You can get rid of the stale processes with:
apache2ctl graceful
and kill those processes with:
pkill -f -x /usr/lib/cgi-bin/php -P 1
scripting and scheduling those two commands (with proper checks) will avoid the server to host plenty of useless procs, but the issue is still present.