PHP uses memcache to realize multi-server shared session

[Session]
; Handler used to store/retrieve data.
session.save_handler = files; This is the session method, the default files is enough, which means file storage.

There are two other ways, user and memcache. The user mode refers to the handle of the session defined by oneself (that is, the user), which is used for session access, etc. This can store the session extension in the database. In memcache mode, you need to configure memcache and session.save_path.

Use memcache for PHP’s session.save_handler:

ini_set("session.save_handler", "memcache");
ini_set("session.save_path", "tcp://127.0.0.1:11211,tcp://192.168.1.12:11211") ;

Use memcached for PHP's session.save_handler:

ini_set("session.save_handler","memcached");
ini_set("session.save_path","127.0.0.1:11211");

The following introduces how PHP implements memcache sharing for multi-server session sharing. example: Customize session processing mechanism.

/* vim: set expandtab tabstop=4 shiftwidth=4 foldmethod=marker: */
//==================== ========================
// Program: Memcache-Based Session Class
// Function: Session function class based on Memcache storage
//= ==========================================

/**
 * File: MemcacheSession.inc.php
 * Class name: MemcacheSession Class
 * Function: Independently implement the Session function based on Memcache storage
 * Description: This class is to implement the Session function, basically through
 * Set the client's Cookie To save the SessionID,
 * then save the user's data on the server side, and finally determine whether a data belongs to the user through
 * the Session Id in the cookie,
 * and then perform corresponding data operations
 *
 * This method is suitable for Memcache The way to store session data in memory,
 * At the same time, if you build a distributed Memcache server,
 * can save a lot of cached data, and is suitable for situations where there are a lot of users and large concurrency
 *
 * Note: This class must require PHP The Memcache extension is installed or the PHP API of Memcache is required
 * To obtain the Memcache extension, please visit: http://pecl.php.net
 */

//Set the SESSION validity time in seconds
define('SESS_LIFTTIME', 3600);

//Define memcache configuration information
define('MEMCACHE_HOST', 'localhost');
define('MEMCACHE_PORT' ', '10000');

if (!defined('MemcacheSession'))
{
 define('MemcacheSession', TRUE);
 class MemacheSession
 {
 // {{{ Class member attribute definition
 static $mSessSavePath ;
 static $mSessName;
 static $mMemcacheObj;
 // }}}

 // {{{ Initialization constructor
 /**
 * Constructor
 *
 * @param string $login_user Login user
 * @param int $login_type User type
 * @param string $login_sess Login Session value
 * @return Esession
*/
 public function __construct()
 {
 //My memcache It is compiled as a php module and can be called directly
 //If not, please include the Memcache-client.php file yourself
 if (!class_exists('Memcache') || !function_exists('memcache_connect'))
 {
 die('Fatal Error:Can not load Memcache extension!');
 }

 if (!empty(self::$mMemcacheObj) && is_object(self::$mMemcacheObj))
 {
 return false;
 }

 self::$mMemcacheObj = new Memcache;

 if (!self::$mMemcacheObj->connect(MEMCACHE_HOST , MEMCACHE_PORT))
 {
 die('Fatal Error: Can not connect to memcache host '. MEMCACHE_HOST . ':'. MEMCACHE_PORT);
 }

 return TRUE;
 }
 // }}}

 /**{{{ sessOpen($pSavePath, $name)
     *
     * @param   String  $pSavePath
     * @param   String  $pSessName
     *
     * @return  Bool    TRUE/FALSE
*/
 public function sessOpen($pSavePath = '', $pSessName = '')
 {
 self::$mSessSavePath = $pSavePath;
 self::$mSessName = $pSessName;
 return TRUE;
 }
 // }}}

 /**{{{ sessClose()
     *
     * @param   NULL
     *
     * @return  Bool    TRUE/FALSE
*/
 public function sessClose()
 {
 return TRUE;
 }
 // }}}

 /**{{{ sessRead($wSessId)
     *
     * @param   String  $wSessId
     *
     * @return  Bool    TRUE/FALSE
*/
 public function sessRead($wSessId = '')
 {
 $wData = self::$mMemcacheObj->get( $wSessId);

 //Read the data first, if not, initialize one
 if (!empty($wData))
 {
 return $wData;
 }
 else
 {
 //Initialize an empty record
 $ ret = self::$mMemcacheObj->set($wSessId, '', 0, SESS_LIFTTIME);
 if (TRUE != $ret)
 {
 die("Fatal Error: Session ID $wSessId init failed!") ;
 return FALSE;
 }
 return TRUE;
 }
 }
 // }}}

 /**{{{ sessWrite($wSessId, $wData)
     *
     * @param   String  $wSessId
     * @param   String  $wData
     *
     * @return  Bool    TRUE/FALSE
*/
 public function sessWrite($wSessId = '', $wData = '')
 {
 $ret = self::$mMemcacheObj->replace($wSessId, $wData, 0 , SESS_LIFTTIME);
 if (TRUE != $ret)
 {
 die("Fatal Error: SessionID $wSessId Save data failed!");
 return FALSE;
 }
 return TRUE;
 }
 // }}}

 /**{{{ sessDestroy($wSessId)
     *
     * @param   String  $wSessId
     *
     * @return  Bool    TRUE/FALSE
*/
 public function sessDestroy($wSessId = '')
 {
 self::sessWrite($wSessId);
 return FALSE;
 }
 // }}}

 /** {{{ sessGc()
     *
     * @param   NULL
     *
     * @return  Bool    TRUE/FALSE
*/
 public function sessGc()
 {
 //No additional recycling required, memcache has its own expired recycling mechanism
 return TRUE;
 }
 // }}}

 /**{{{ initSess()
     *
     * @param   NULL
     *
     * @return  Bool    TRUE/FALSE
*/
 public function initSess()
 {
 //Do not use GET/POST variable method
 ini_set('session.use_trans_sid', 0);

 //Set the maximum lifetime of garbage collection
 ini_set('session.gc_maxlifetime', SESS_LIFTTIME) ;

 //How to use COOKIE to save SESSION ID
 ini_set('session.use_cookies', 1);
 ini_set('session.cookie_path', '/');

 $domain = '.imysql.cn';
 //Multiple hosts share the COOKIE that saves the SESSION ID
 ini_set('session.cookie_domain', $domain);

 //Set session.save_handler to user instead of the default files
 session_module_name('user');

 //Define the method names corresponding to various SESSION operations:
 session_set_save_handler(
 array('MemacheSession', 'sessOpen'), //corresponds to the static method My_Sess::open(), the same below.
 array('MemacheSession', 'sessClose'),
 array('MemacheSession', 'sessRead'),
 array('MemacheSession', 'sessWrite'),
 array('MemacheSession', 'sessDestroy'),
 array ('MemacheSession', 'sessGc')
 );

 session_start();
 return TRUE;
 }
 // }}}
 }//end class
}//end define

$memSess = new MemacheSession;
$memSess->initSess();
?>

Include MemacheSession.inc.php directly in the header file in the program to use this class.

Test example. 1. Create a session

//set_session.php
session_start();
if (!isset($_SESSION['admin'])) {
 $_SESSION['TEST'] = 'wan';
}
print $_SESSION['admin'];
print "/n";
print session_id();
?>

2, use sessionid to query in memcached:

//get_session.php
$mem = new Memcache;
$mem->connect("127.0.0.1", 11211);
var_dump($mem->get( '0935216dbc0d721d629f89efb89affa6'));
?>

Note: memcache PECL In future versions, you can directly set php.ini to set session.save_handler.

For example:

session.save_handler = memcache session.save_path = "tcp://host:port?persistent=1&weight=2&timeout=2&retry_interval=15,tcp://host2:port2"