I am having this issue with a new box where Apache at random serves blank pages and won't serve anything but until it's restarted. I see no errors in /var/log/messages either to show why this is happening. It's not all pages either just several various ones. I know it's not a programming issue either because the only thing the server is running is one instance of vBulletin. I look at top during this and CPU and RAM usage are very low. The only fix to get Apache to serve the pages is to restart it. Anyone have any clues on what it could be? I set my php.ini memory limit to a gig (I have 16 gigs in the sever) but that was no help.
Have you tested a static HTML page? If the server is setup to not print out PHP errors you will get blank pages rather than php errors. If this is the case check out the error_log in the scripts directory, it might be massive.
Well apache usally only serves blank pages when there is a error in the script itself, could it possibley be a permissions problem (the script trying to access a file after a certin amount of time) or possibley a database issue ? ie hitting max database connections and failing. without any details can't do anything except generic ideas.