Server throws errors from time to time randomly

[eluser]Unknown[/eluser]
Have a same problem.
try restart apache problem in apache.
I do not know what exactly you want to change the settings in Apache, but reboot helps temporarily
for debian: sudo /etc/init.d/apache2 restart


php 5.3.3
ci 2.1.3
server dedicated, cpu usage low, 10 gb ram free, traffic 50000pages per day.