yii1.1.3主从(多从)、读写分离配置

从新配置main.php片段

代码如下

-----------------------------------------------------------

'db'=>array(
   'connectionString' => 'sqlite:'.dirname(__FILE__).'/../data/testdrive.db',
),
// uncomment the following to use a MySQL database
      //////////////////////////////////////////////////////
      'db'=>array(

          'class'=>'application.extensions.DbConnectionMan',//扩展路径

          'connectionString' => 'mysql:host=localhost;dbname=test',//主数据库 写

          'emulatePrepare' => true,

          'username' => 'root',

          'password' => '5201314',

          'charset' => 'utf8',

          'tablePrefix' => '', //表前缀

          'enableSlave'=>true,//从数据库启用

          //'urgencyWrite'=>true,//紧急情况 主数据库无法连接 启用从数据库 写功能

          //'masterRead'=>true,//紧急情况 从数据库无法连接 启用主数据库 读功能

          'slaves'=>array(//从数据库

              array(   //slave1

                  'connectionString'=>'mysql:host=localhost;dbname=test2',

                  'emulatePrepare' => true,

                  'username'=>'root',

                  'password'=>'5201314',

                  'charset' => 'utf8',

                  'tablePrefix' => '', //表前缀

              ),

              array(   //slave2

                  'connectionString'=>'mysql:host=localhost;dbname=test3',

                  'emulatePrepare' => true,

                  'username'=>'root',

                  'password'=>'5201314',

                  'charset' => 'utf8',

                  'tablePrefix' => '', //表前缀

              ),
          ),
      ),

-----------------------------------------------------------

在protected/extensions中新建文件名DbConnectionMan.php

代码如下

----------------------------------------

<?php

/**

 * 主数据库 写 从数据库（可多个）读

 * 实现主从数据库 读写分离 主服务器无法连接 从服务器可切换写功能

 * 从务器无法连接 主服务器可切换读功

 * by lmt

 * */

class DbConnectionMan extends CDbConnection {

    public $timeout = 10; //连接超时时间

    public $markDeadSeconds = 600; //如果从数据库连接失败 600秒内不再连接

    //用 cache 作为缓存全局标记

    public $cacheID = 'cache';

    /**

     * @var array $slaves.Slave database connection(Read) config array.

     * 配置符合 CDbConnection.

     * @example

     * 'components'=>array(

     *   'db'=>array(

     *    'connectionString'=>'mysql://<master>',

     *    'slaves'=>array(

     *     array('connectionString'=>'mysql://<slave01>'),

     *     array('connectionString'=>'mysql://<slave02>'),

     *    )

     *   )

     * )

     * */

    public $slaves = array();

    /**

     *

     * 从数据库状态 false 则只用主数据库

     * @var bool $enableSlave

     * */

    public $enableSlave = true;

    /**

     * @var slavesWrite 紧急情况主数据库无法连接 切换从服务器（读写）.

     */

    public $slavesWrite = false;

    /**

     * @var masterRead 紧急情况从主数据库无法连接 切换从住服务器（读写）.

     */

    public $masterRead = false;

    /**

     * @var _slave

     */

    private $_slave;

    /**

     * @var _disableWrite 从服务器（只读）.

     */

    private $_disableWrite = true;

    /**

     *

     * 重写 createCommand 方法,1.开启从库 2.存在从库 3.当前不处于一个事务中 4.从库读数据

     * @param string $sql

     * @return CDbCommand

     * */

    public function createCommand($sql = null) {

        if ($this->enableSlave && !empty($this->slaves) && is_string($sql) && !$this->getCurrentTransaction() && self::isReadOperation($sql) && ($slave = $this->getSlave())

        ) {

            return $slave->createCommand($sql);

        } else {
//            if (!$this->masterRead) {
//
//                if ($this->_disableWrite && !self::isReadOperation($sql)) {
//
//                    throw new CDbException("Master db server is not available now!Disallow write operation on slave server!");
//
//                }
//
//            }

            return parent::createCommand($sql);

        }

    }

    /**

     * 获得从服务器连接资源

     * @return CDbConnection

     * */

    public function getSlave() {

        if (!isset($this->_slave)) {

            shuffle($this->slaves);

            foreach ($this->slaves as $slaveConfig) {

                if ($this->_isDeadServer($slaveConfig['connectionString'])) {

                    continue;

                }

                if (!isset($slaveConfig['class']))

                    $slaveConfig['class'] = 'CDbConnection';

                $slaveConfig['autoConnect'] = false;

                try {

                    if ($slave = Yii::createComponent($slaveConfig)) {

                        Yii::app()->setComponent('dbslave', $slave);

                        $slave->setAttribute(PDO::ATTR_TIMEOUT, $this->timeout);

                        $slave->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);

                        $slave->setActive(true);

                        $this->_slave = $slave;

                        break;

                    }

                } catch (Exception $e) {

                    $this->_markDeadServer($slaveConfig['connectionString']);

                    Yii::log("Slave database connection failed!ntConnection string:{$slaveConfig['connectionString']}", 'warning');

                    continue;

                }

            }

            if (!isset($this->_slave)) {

                $this->_slave = null;

                $this->enableSlave = false;

            }

        }

        return $this->_slave;

    }

    public function setActive($value) {

        if ($value != $this->getActive()) {

            if ($value) {

                try {

                    if ($this->_isDeadServer($this->connectionString)) {

                        throw new CDbException('Master db server is already dead!');

                    }

                    //PDO::ATTR_TIMEOUT must set before pdo instance create

                    $this->setAttribute(PDO::ATTR_TIMEOUT, $this->timeout);

                    $this->open();

                } catch (Exception $e) {

                    $this->_markDeadServer($this->connectionString);

                    $slave = $this->getSlave();

                    Yii::log($e->getMessage(), CLogger::LEVEL_ERROR, 'exception.CDbException');

                    if ($slave) {

                        $this->connectionString = $slave->connectionString;

                        $this->username = $slave->username;

                        $this->password = $slave->password;

                        if ($this->slavesWrite) {

                            $this->_disableWrite = false;

                        }

                        $this->open();

                    } else { //Slave also unavailable

                        if ($this->masterRead) {

                            $this->connectionString = $this->connectionString;

                            $this->username = $this->username;

                            $this->password = $this->password;

                            $this->open();

                        } else {

                            throw new CDbException(Yii::t('yii', 'CDbConnection failed to open the DB connection.'), (int) $e->getCode(), $e->errorInfo);

                        }

                    }

                }

            } else {

                $this->close();

            }

        }

    }

    /**

     * 检测读操作 sql 语句

     *

     * 关键字： SELECT,DECRIBE,SHOW ...

     * 写操作:UPDATE,INSERT,DELETE ...

     * */

    public static function isReadOperation($sql) {

        $sql = substr(ltrim($sql), 0, 10);

        $sql = str_ireplace(array('SELECT', 'SHOW', 'DESCRIBE', 'PRAGMA'), '^O^', $sql); //^O^,magic smile
        return strpos($sql, '^O^') === 0;

    }

    /**

     * 检测从服务器是否被标记 失败.

     */

    private function _isDeadServer($c) {

        $cache = Yii::app()->{$this->cacheID};

        if ($cache && $cache->get('DeadServer::' . $c) == 1) {

            return true;

        }

        return false;

    }

    /**

     * 标记失败的slaves.

     */

    private function _markDeadServer($c) {

        $cache = Yii::app()->{$this->cacheID};

        if ($cache) {

            $cache->set('DeadServer::' . $c, 1, $this->markDeadSeconds);

        }

    }

}

-----------------------------------------

配置完毕，接下来在控制器中测试代码如下

----------------------------

$goods = new goods();
$d = $goods->findAll();
foreach($d AS $k =>$v){
    echo $v->name;
}
$goods->name='test insert aaaa';
$goods->insert();

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