So to start of with I know that using a memcache or a database would be a better way to go. But I have (for now) made a load balance environment where I have a shared PHP session file storage. Some customers now claim they experience some problem and I am not sure if it have anything to do with the session storage.
My question is - how does PHP handle a shared php session file storage? Will there be problems with the session ID's they are given? (since its 3-4 Apache2/PHP machines running creating sessions) How about the clean up when they are marked as garbage? Can one apache2/PHP machine by "accident" delete a session not intended to be deleted yet? All the machines have the same "marked as garbage" timeout. And they all run the same PHP session clean up cronjob.