MySQL Master-Slave(複数) 構成への接続設定。 ref: http://qiita.com/nntsugu@github/items/b6e5b7951ede5664578d

Base.php

<?php

class Base extends Phalcon\Mvc\Model
{
    public function initialize()
    {
        $this->setWriteConnectionService('dbMaster');
        $this->setReadConnectionService('dbSlave');
    }
}

config.php

<?php
   (中略)

   // masterの設定だよ
   $settings = array_merge(
        $settings,
        array(
            'mysql_master' => array(
                'adapter' => 'Mysql',
                'host' => '[hostname(master)]:[port]', // ex localhost:3306
                'username' => 'user',
                'password' => 'pass',
                'dbname' => 'database',
            ),
        )
    );

    // slave x3の設定だよ
    $slave1 = '[hostname(slave1)]:[port]'; // ex localhost:3316
    $slave2 = '[hostname(slave2)]:[port]'; // ex localhost:3326
    $slave3 = '[hostname(slave3)]:[port]'; // ex localhost:3336
    $mysqlSlaves = array(
        'mysql_slave1' => array(
            'adapter' => 'Mysql',
            'host' => $slave1,
                 'username' => 'user',
                'password' => 'pass',
                'dbname' => 'database',
        ),
        'mysql_slave2' => array(
            'adapter' => 'Mysql',
            'host' => $slave2,
                 'username' => 'user',
                'password' => 'pass',
                'dbname' => 'database',
        ),
        'mysql_slave3' => array(
            'adapter' => 'Mysql',
            'host' => $slave3,
                 'username' => 'user',
                'password' => 'pass',
                'dbname' => 'database',
        ),
    );

    // ちょっと回りくどい書き方しているのはここでslaveの台数をカウントしたいから。
    $settings = array_merge(
        $settings,
        $mysqlSlaves,
        array('mysql_slave_count' => count($mysqlSlaves))
    );

   (以下略)

file3.txt

    $this->setWriteConnectionService('dbMaster');

file4.txt

    $this->setReadConnectionService('dbSlave');

file7.php

<?php

$robots = new Robots();

$robots->find(); // dbSlaveへ接続
（略）
$robots->save(); // dbMasterへ接続

Robots.php

<?php

class Robots extends Base
{
（略）
}

service.php

<?php
   (中略)

// MySQL master
$di->set('dbMaster', function () use ($config) {
    return new DbAdapter(array(
        'host' => $config->mysql_master->host,
        'username' => $config->mysql_master->username,
        'password' => $config->mysql_master->password,
        'dbname' => $config->mysql_master->dbname
    ));
});
// MySQL slave
// slaveの中から１台ランダムに選択。randの上限指定にさっきのslave台数を使ってます。
$di->set('dbSlave', function () use ($config) {
    $slaveName = 'mysql_slave' . (String)rand(1, $config->mysql_slave_count);
    return new DbAdapter(array(
        'host' => $config[$slaveName]['host'],
        'username' => $config[$slaveName]['username'],
        'password' => $config[$slaveName]['password'],
        'dbname' => $config[$slaveName]['dbname']
    ));
});

   (以下略)

構成

/app
  /config
     config.php
     service.php
  /models
     Base.php  // 名前は好きにしてOK