Memcached 安装与配置
最新的稳定版: wget http://monkey.org/~provos/libevent-1.4.14b-stable.tar.gz
wget http://memcached.googlecode.com/files/memcached-1.4.5.tar.gz
wget http://pecl.php.net/get/memcache-1.4.tgz （最好是根据相应的版本来选择）
安装libevent
tar zxvf libevent-1.4.14b-stable.tar.gz
cd libevent-1.4.14b-stable
./configure --prefix=/usr/local/libevent/
make
make install
安装memcached
tar zxvf memcached-1.4.5.tar.gz -C /usr/src
cd /usr/src/memcached-1.4.5
./configure --prefix=/usr/local/memcached/ --with-libevent=/usr/local/libevent
make && make install
运行memcached
/usr/local/memcached -d -m 128 -l localhost -p 11211 -u root
#说明：
# -d 设置 memcached 可以使用的内存大小，单位为 M ；
# -l 设置监听的 IP 地址，如果是本机的话，通常可以不设置此参数 ；
# -p 设置监听的端口，默认为 11211，所以也可以不设置此参数；
# -u 指定用户;
#如果遇到运行memcached时遇到问题，错误提示如下：
# /usr/local/servers/memcached/bin/memcached: error while loading shared libraries: libevent-1.4.so.2: cannot open shared object file: No such file or directory
则运行 LD_DUBUG=libs 就可以知道memcached启动时库的加载路径。具体如下:
# LD_DEBUG=libs /usr/local/servers/memcached/bin/memcached -v
10929: find library=libevent-1.4.so.2 [0]; searching
10929: search cache=/etc/ld.so.cache
10929: search path=/lib/tls/i686/sse2:/lib/tls/i686:/lib/tls/sse2:/lib/tls:/lib/i686/sse2:/lib/i686:/lib/sse2:/lib:/usr/lib/tls/i686/sse2:/usr/lib/tls/i686:/usr/lib/tls/sse2:/usr/lib/tls:/usr/lib/i686/sse2:/usr/lib/i686:/usr/lib/sse2:/usr/lib (system search path)
10929: trying file=/lib/tls/i686/sse2/libevent-1.4.so.2
10929: trying file=/lib/tls/i686/libevent-1.4.so.2
10929: trying file=/lib/tls/sse2/libevent-1.4.so.2
10929: trying file=/lib/tls/libevent-1.4.so.2
10929: trying file=/lib/i686/sse2/libevent-1.4.so.2
10929: trying file=/lib/i686/libevent-1.4.so.2
10929: trying file=/lib/sse2/libevent-1.4.so.2
10929: trying file=/lib/libevent-1.4.so.2
10929: trying file=/usr/lib/tls/i686/sse2/libevent-1.4.so.2
10929: trying file=/usr/lib/tls/i686/libevent-1.4.so.2
10929: trying file=/usr/lib/tls/sse2/libevent-1.4.so.2
10929: trying file=/usr/lib/tls/libevent-1.4.so.2
10929: trying file=/usr/lib/i686/sse2/libevent-1.4.so.2
10929: trying file=/usr/lib/i686/libevent-1.4.so.2
10929: trying file=/usr/lib/sse2/libevent-1.4.so.2
10929: trying file=/usr/lib/libevent-1.4.so.2
10929:
然后给libevent-1.4.so.2建立一个链接后再运行memcached：
# ln -s /usr/local/servers/libevent/lib/libevent-1.4.so.2 /lib/libevent-1.4.so.2
安装php的memcache扩展
可以使用自带的pecl安装程序
#/usr/local/php/bin/pecl install memcache
#从源码安装
# tar zxvf memcache-1.4.tgz -C /usr/src
# cd /usr/src/memcached-1.4
# ./configure --prefix=/usr/local/memcache --enable-memcache --with-php-config=/usr/local/php/bin/php-config --with-zlib-dir
# make && make install
#安装完后会有类似这样的提示：
#Installing shared extensions: /usr/local/servers/php5/lib/php/extensions/no-debug-non-zts-20060922/
#把这个记住，然后修改php.ini，
# vim /etc/php.ini
extension_dir = "./"
修改为
extension_dir = "/usr/local/php/lib/php/extensions/"
重启php-fpm
/etc/rc.d/init.d/php-fpm restart
重启nginx
/usr/local/nginx/sbin/nginx -s reload
php里使用phpinfo()看到如下信息说明memcached扩展才算安装好！
