安装php7的memcached扩展
1.编译安装libmemcached-1.0.18
wget https://launchpadlibrarian.net/165454254/libmemcached-1.0.18.tar.gztar -zxvf libmemcached-1.0.18.tar.gz
cd libmemcached-1.0.18
./configure --prefix=/usr/local/libmemcached --with-memcached
make && make install2. 安装php-memcached扩展
php使用memcache的扩展有两个，一个memcache，一个memcached，前者比较老，推荐使用第二个，我们这里以第二个为例：在github上找到适用于php7的分支（https://github.com/php-memcached-dev/php-memcached/tree/php7），同样使用wget下载zip压缩包，解压缩，进入目录，依次执行下列命令（其中php-config和libmemcached目录根据具体情况设定，可以使用whereis或者find来查找

# 解压
cd php-memcached-php7# 执行phpize会生成configure文件
/usr/local/php/bin/phpize
# 执行预编译
./configure --enable-memcached --with-php-config=/usr/local/php/bin/php-config --with-libmemcached-dir=/usr/local/libmemcached --disable-memcached-sasl
make
make install[root@szxxlfhtest02t:/usr/local/src/php-memcached-php7]# /usr/local/php/bin/phpize
Configuring for:
PHP Api Version:         20151012
Zend Module Api No:      20151012
Zend Extension Api No:   320151012[root@szxxlfhtest02t:/usr/local/src/php-memcached-php7]# make install
Libraries have been installed in:/usr/local/src/php-memcached-php7/modulesIf you ever happen to want to link against installed libraries
in a given directory, LIBDIR, you must either use libtool, and
specify the full pathname of the library, or use the `-LLIBDIR'
flag during linking and do at least one of the following:- add LIBDIR to the `LD_LIBRARY_PATH' environment variable
     during execution- add LIBDIR to the `LD_RUN_PATH' environment variable
     during linking- use the `-Wl,--rpath -Wl,LIBDIR' linker flag- have your system administrator add LIBDIR to `/etc/ld.so.conf'

See any operating system documentation about shared libraries for
more information, such as the ld(1) and ld.so(8) manual pages.
----------------------------------------------------------------------Build complete.
Don't forget to run 'make test'.

Installing shared extensions:     /usr/local/php-7.0.12_fpm/lib/php/extensions/no-debug-non-zts-20151012/修改php.ini的配置
加上：extension_dir="/usr/local/php7.1/lib/php/extensions/no-debug-non-zts-20160303/"(每个人的路径可能不一样)extension = "memcached.so
重启php-fpm3. 修改php.ini文件
（php.ini文件具体位置可以通过phpinfo()函数来查看到），在php.ini文件之中加入下面这句：# vim /usr/local/php-7.0.12_fpm/lib/php.ini
extension_dir="/usr/local/php-7.0.12_fpm/lib/php/extensions/no-debug-non-zts-20151012/"
extension=memcached.so[root@szxxlfhtest02t:~]# php -m
[PHP Modules]
bz2
calendar
Core
ctype
curl
date
dba
dom
exif
fileinfo
filter
ftp
gd
gettext
hash
iconv
json
ldap
libxml
mbstring
mcrypt
memcache
memcached4.测试是否安装成功[root@szxxlfhtest02t:/data/www/vhosts/cmstest.chinasoft.com/httpdocs]# cat mem.php
<?php$mem  = new Memcached(); //创建一个memcached对象
$mem->addServer('127.0.0.1',11211);    //连接memcached
$mem->set("key","test");//设置一个变量到内存中，名称是key 值是test
$get_value = $mem->get('key'); //从内存中取出key的值
if($mem->getResultCode() == Memcached::RES_NOTFOUND)    //如果该名称的变量没有设置
{echo 'not set!';
}
else
{echo $get_value;
}***************************[root@newcms:/data/www/cms/cmsx.chinasoft.com.wx/httpdocs/public]# cat /usr/local/nginx/conf/cms.d/cmsx.chinasoft.com.wx.conf
server {listen 80;server_name     cmsx.chinasoft.com.wx cmsx.chinasoft.com.wx.wx;access_log      /data/www/logs/nginx_log/access/cmsx.chinasoft.com.wx_access.log main ;access_log on;error_log       /data/www/logs/nginx_log/error/cmsx.chinasoft.com.wx_error.log ;root            /data/www/cms/cmsx.chinasoft.com.wx/httpdocs/public/;index           index.html index.shtml index.php ;include         rewrite.d/cmsx.chinasoft.com.wx.conf ;error_page  404 403              /404.html;    access_log on;#location / {#                expires -1;#                proxy_pass http://php_pool;
        #                include proxy_params;#}#location / {#        index  index.php index.html index.htm;#        try_files $uri $uri/ /index.php?$query_string;#}#location ~ \.php$ {#        fastcgi_pass   unix:/tmp/php-cgi.sock;#        fastcgi_index  index.php;#        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;#        include        fastcgi_params;#}location / {index index.php index.html index.htm;if (!-e $request_filename) {rewrite . /index.php last;}}location ~ \.php$ {fastcgi_pass unix:/tmp/php-cgi.sock;fastcgi_index index.php;fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;include fastcgi_params;}}