**PHP版本：**PHP 7.3.16 **LINUX版本：**7.6
安装成功的样子：
php -r "phpinfo();" | grep memcache
memcache
memcache support => enabled
memcache.allow_failover => 1 => 1
memcache.chunk_size => 32768 => 32768
memcache.compress_threshold => 20000 => 20000
memcache.default_port => 11211 => 11211
memcache.hash_function => crc32 => crc32
memcache.hash_strategy => consistent => consistent
memcache.lock_timeout => 15 => 15
memcache.max_failover_attempts => 20 => 20
memcache.prefix_host_key => 0 => 0
memcache.prefix_host_key_remove_subdomain => 0 => 0
memcache.prefix_host_key_remove_www => 1 => 1
memcache.prefix_static_key => no value => no value
memcache.protocol => ascii => ascii
memcache.redundancy => 1 => 1
memcache.session_prefix_host_key => 0 => 0
memcache.session_prefix_host_key_remove_subdomain => 0 => 0
memcache.session_prefix_host_key_remove_www => 1 => 1
memcache.session_prefix_static_key => no value => no value
memcache.session_redundancy => 2 => 2
memcache.session_save_path => no value => no value
安装步骤：
# 下载 memcache 源码包
wget https://github.com/websupport-sk/pecl-memcache/archive/NON_BLOCKING_IO_php7.zip
# 解压缩
unzip NON_BLOCKING_IO_php7.zip
# 进入解压后的目录
cd pecl-memcache-NON_BLOCKING_IO_php7/
# 生成配置文件
/usr/local/php/bin/phpize
# 配置
./configure --with-php-config=/usr/local/php/bin/php-config
make
make install
# 在 php.ini 中添加扩展
extension=memcache
# 重启服务
# 可以使用下面三种方式中的一种(具体看php的安装方式)
service php-fpm restart
kill -USR2 `cat /usr/local/php/var/run/php-fpm.pid`
systemctl reload php-fpm
