PHP7安裝memcached，提升網頁速度
OS
CentOS Linux release 7.3.1611 (Core)
PHP 7.0.18 (cli) (built: Apr 15 2017 07:09:11) ( NTS )
安裝
# yum install epel-release
# yum install memcached
# yum install php70w-pecl-memcached
完裝完畢後會多一個檔案：
/etc/php.d/z-memcached.ini
設定
vi /etc/sysconfig/memcached
PORT="11211"
USER="memcached"
MAXCONN="3000"
CACHESIZE="200"
OPTIONS="-l 127.0.0.1"
第3行最大連線數；
第4行記憶體大小，單位是mb
第5行限定監聽介面，若留空就全部介面
# vi /etc/php.ini
session.save_path = "127.0.0.1:11211"
啟動
# systemctl start memcached
# systemctl restart httpd
檢查php模組
# php -m | grep memcached
memcached <一片空白代表你沒裝好>
查看Memcached狀態
物件清單
# memcached-tool 127.0.0.1:11211
# memcached-tool 127.0.0.1:11211 display
統計資料
# memcached-tool 127.0.0.1:11211 stats
物件內容
# memcached-tool 127.0.0.1:11211 dump
其他
1. 設定開機啟動
systemctl enable memcached
2. PHP的session原本存在 /var/lib/php/session/ 改成 memcached後就不會再存於此
3. 重啟 apache不會清除資料，但重啟memcached會。
4. Codeigniter3 在PHP7使用memcached會遇到問題，目前尚無法解決(只能關掉錯誤)
$ vi application/config/config.php
$config['sess_save_path'] = '127.0.0.1:11211'; //NULL;
A PHP Error was encountered
Severity: Warning
Message: Memcached::touch(): using touch command with binary protocol is not recommended with libmemcached versions below 1.0.18, please use ascii protocol or upgrade libmemcached
Filename: drivers/Session_memcached_driver.php
參考資料
[2] https://www.cyberciti.biz/faq/rhel-fedora-linux-install-memcached-caching-system-rpm/
[3] http://php.net/manual/en/memcached.sessions.php#99646
[4] https://blog.longwin.com.tw/2010/04/use-memcached-store-php-session-2010/