Until last week I had a working configuration of my managed server that was set up to run under PHP4 while all the subdomains ran PHP5 (everything else was a typical LAMP configuration). So it looked like this:
PHP4 (globally set):
PHP5 (via .htaccess and php.ini):
Now I finally updated the global configuration to PHP5.3 FastCGI and all the subdomains stopped working. I disabled the .htaccess and php.ini settings too - to no success :-(
The behaviour is as follows:
As far as I can tell no error logs are written. The concerned projects are all major well known applications (including a Magento installation which - luckily - is still in development). I tried a new install of the Revive AdServer which should support FastCGI - but it shows the same behaviour again.
I am absulutely at the end of my knowledge and so hoping you guys have an idea what it could be.
After trying EVERY(!!!) possible variation of my default php.ini settings in a sandbox I found the following setting to be the reason:
session.auto_start = On
This seems to be an incompatible setting for at least Magento 1.8 as well as for the Revive Adverver. Both stopped showing the erroneous behaviour as soon as I changed that. As for symfony I can not yet tell, but I guess it won't matter much as symfony doesn't come as a "ready-to-use" anyway.
Just as foot note and for people who run into the same kind of behaviour: Revive Adverver generated the following error.log:
PHP Fatal error: OX_Admin_UI_Install_InstallController::initInstallStatus() [ox-admin-ui-install-installcontroller.initinstallstatus]: The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "OX_Admin_UI_Install_InstallStatus" of the object you are trying to operate on was loaded before unserialize() gets called or provide a __autoload() function to load the class definition in /lib/OX/Admin/UI/Install/InstallController.php on line 134