Install memcached from source

Even if you have the latest version of CentOS then the memcached version can be many years behind.

If you have a current version installed, you can place the latest version of the top by running the following:

yum -y install libevent-devel

wget http://www.memcached.org/files/memcached-1.6.40.tar.gz

tar -zxvf memcached-1.6.40.tar.gz
cd memcached-1.6.40
./configure --prefix=/usr && make && sudo make install

service memcached restart