鑒於上次的デュエル学園因為讀取速度太慢造成很多時間差上面的BUG
這次的モバゲーアプリ決定使用Memcached和SESSION來解決
由於視同時使用多台前端SERVER然後又特別準備了一臺Memcache SERVER
所以就必須把SESSION存到Memcache SERVER中囉！

首先是先安裝memcached

yum -y install libevent-devel gcc-c++ php  php-pecl-memcache
wget http://memcached.googlecode.com/files/memcached-1.4.5.tar.gz
tar zxvf memcached-1.4.5.tar.gz
cd memcached-1.4.5
./configure
make
make install
memcached -d -m 1024 -p 11211 -u root

啟動參數說明

-d 指定用 daemon 方式
-m 指定使用記憶體容量(單位MB)
-p 指定要監聽的 port (不指定則預設 11211)
-u 指定用哪個帳號來執行，例如 nobody

接著編輯/etc/php5/apache2/php.ini 加上

extension=memcache.so

重新啓動

/etc/init.d/apache2 restart

至於如何使用Memcached來存取SESSION
可以參考一下這個CLASS:

/*
 * Sample code to use SessionManagerMemCache class 
 * 

////////////////////////////////////////////////////////////////////////////////////////
// Add Session Class
require_once("my_class_file_path/class.Session.php");

// Initialize session info here 
$server['info'] = "127.0.0.1";
$server['port'] = "11211";
$sess = new SessionManagerMemCache($server);
if(isset($_REQUEST['sessionId']) && $_REQUEST['sessionId']!="") {
	session_id($_REQUEST['sessionId']);
	// To have the param [sessionId] with all the URLS and form tags 
	output_add_rewrite_var('sessionId', $_REQUEST['sessionId']);
} 
session_start();
////////////////////////////////////////////////////////////////////////////////////////
 * 
 * 
 * */
class SessionManagerMemCache { 
var $lifetime = 0;
var $memcache = null; 

function __construct($server = array('info'=>'xxx.xxx.xxx.xxx', 'port'=>'11211')) { 
 register_shutdown_function("session_write_close");

 $this->lifetime = intval(ini_get("session.gc_maxlifetime"));
 $this->memcache = new Memcache;
 if(!$this->memcache->connect($server['info'], $server['port'])) { 
  die("Memcache server was not connected successfully.");
 } 

 // Register this object as the session handler
 session_set_save_handler( 
  array( &$this, "open" ),
  array( &$this, "close" ),
  array( &$this, "read" ),
  array( &$this, "write"),
  array( &$this, "destroy"),
  array( &$this, "gc" )
 );
} 

function open() {
 return true; 
} 

function read($id) { 
 return $this->memcache->get("sessions/{$id}"); 
}

function write($id, $data) { 
 return $this->memcache->set("sessions/{$id}", $data, MEMCACHE_COMPRESSED, $this->lifetime);
} 

function destroy($id) { 
 return $this->memcache->delete("sessions/{$id}");
}

function gc(){ return true; } 

function close(){ 
 $this->lifetime = null;
 $this->memcache = null;
 return true; 
} 

function __destruct() { 
 session_write_close(); 
} 
}