install

apt-get install -y memcached
sed -i 's|-l 127.0.0.1|-l 172.29.13.117|g' /etc/memcached.conf
service memcached restart

flush cache

telnet mc.example.com 11211
stats
flush_all
quit

flush all cache in OpenStack

# flush all memcached
for NODE in $(openstack network agent list --agent-type dhcp -c Host -f value); do
    echo ${NODE}
    printf "flush_all\nquit\n" | nc -q -1 ${NODE} 11211
done

memcached reserved memory

stats
...
STAT limit_maxbytes 314572800