Warning: Memcache::connect() [memcache.connect]: Can't connect to
localhost:11211, Connection timed out (110) in
/home/revone/public_html/st/main.php on line 3


Check /var/log/messages

you might be able to see something like

tail -f /var/log/messages
Mar 21 08:09:21 server3 kernel: printk: 482 messages suppressed.
Mar 21 08:09:21 server3 kernel: ip_conntrack: table full, dropping packet.
Mar 21 08:09:26 server3 kernel: printk: 435 messages suppressed.
Mar 21 08:09:26 server3 kernel: ip_conntrack: table full, dropping packet.
Mar 21 08:09:31 server3 kernel: printk: 244 messages suppressed.

This means the server is maxing out on kernel sessions that can be handled simultaneously by netfilter in kernel memory.


So, increase this value.

We may increase this by following:

echo "131072" > /proc/sys/net/ipv4/ip_conntrack_max

Aslo edit the sysctl.conf to set this value permanently.

vi /etc/sysctl.conf
+++++++++++++
net.ipv4.netfilter.ip_conntrack_max = 131072
+++++++++++++

sysctl -p