首先必须完成必要的软件安装，memcached是php连接memcached服务器的php扩展它的名字就叫memcached

以前有个叫memcache也是php连接memcached服务器的扩展，它的名字叫memcache

php的memcache和memcached扩展都是作为客户端去连接memcached服务器

但memcached作为客户端比memcache性能更好功能更强大，而且memcache已经停止更新了，因此现在使用扩展的话就用

memcached

接下来安装必要组件：wget  https://launchpad.net/libmemcached/1.0/1.0.18/+download/libmemcached-1.0.18.tar.gz

mkdir /usr/local/libmemcached      

tar xf libmemcached-1.0.18.tar.gz      cd libmemcached-1.0.18

./configure --prefix=/usr/local/libmemcached --with-memcached

make  &&  make install

wget 

tar xf memcached-2.2.0.tgz     cd memcached-2.2.0

/usr/local/php/bin/phpize      (生成configure文件）

./configure --with-php-config=/usr/local/php/bin/php-config  --with-libmemcached-dir=/usr/local/libmemcached --

enable-memcached

make && make install

echo "extension=memcached.so" >> /etc/phpini

service php-fpm restart