I am hosting a PHP/MySQL site on Windows server 2008, PHP v5.4, IIS 6.1. The PHP install was set up by the hosting company as part of Plesk. It is a development site so there is almost zero traffic at present but despite this, every so often php-cgi.exe starts multiple processes which, occasionally reach the maximum memory available on the server and bring my site down.
The increases in memory use do not appear to correlate with times when there would be visitors. They occur a few times during the day (not sure if there is a pattern) but I've noticed that at about 11:15pm every night it seems to happen.
I've tried looking in Windows Application logs but nothing seems to show and IIS logs don't appear to have anything. I'm not running a scheduled job (that I know of) that would cause this.
Please could anyone advise me on what this might be? The server has 1GB RAM and hosts only one very basic site.