memcache官网：memcached.org
下载memcached：https://github.com/memcached/memcached/releases
目前最新版是1.5.3：http://www.memcached.org/files/memcached-1.5.3.tar.gz
安装很简单：
apt-get install libevent-dev ./configure --prefix=/opt/program/memcached make make install
启动memcached：
memcached -d -m 64 -p 11211 -u memcache -l 127.0.0.1