Hi,

I run a server with nginx at the front and apache at the background. Nginx serves as a reverse proxy in here. As there were lots of DOS attacks, I have implemented Deflate-DDOS, APF and Nginx anti-ddos features and the server runs without a problem.
Once every month, the load on server increases upto 300 and I receive an email like this :

Subject : Cron <root@server> [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 | xargs -n 200 -r -0 rm

Content :
find: `/var/lib/php5/sess_0ca40520ac8ecb66090746f90da17516': No such file or directory
find: `/var/lib/php5/sess_3839b0cbf042934183d56ff682c948e0': No such file or directory
find: `/var/lib/php5/sess_dec1ed8ea1f62caf7a42a29b9f82c506': No such file or directory
find: `/var/lib/php5/sess_0532eaf082ace26a36c224a552498a83': No such file or directory
find: `/var/lib/php5/sess_2833be4f2aab6eaef84340d8f6446ab8': No such file or directory
find: `/var/lib/php5/sess_afd6ef56150a9aa389c170fb82f660c8': No such file or directory
find: `/var/lib/php5/sess_6bb00f227bce3710ebc4db2380a42e06': No such file or directory
find: `/var/lib/php5/sess_d766e7932cc2616a3a8895c5b21900a1': No such file or directory
....

There's more that 100,000 ( I suppose ) lines on this email. I have no idea what the problem is. It seems there's something with the session, but I really don't know what it is.
I would appreciate if anyone can help
Thanks in advance

Check your PHP documentation for session data storage and related garbage collection. Decide how long sessions need to remain active and check that with your php.ini "session.gc_.*" variables, change the 'find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 | xargs -n 200 -r -0 rm' line to read 'find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -print0 2>/dev/null | xargs -n 200 -r -0 rm 2>/dev/null' (redirect errors to the bit bucket) and change the cronjob to run more often (the more gradual operations are done the less strain it puts on the system).