CakePHP --- Load Balancing and MySQL Master and Slaves

http://bakery.cakephp.org/articles/eagerterrier/2007/05/26/load-balancing-and-mysql-master-and-slaves-2

If you are currently using MySql master/slave replication for load balancing and wish to transport to cakePHP, it really couldn't be easier.

2 simple steps to master/slave replication in cake..

Firstly in app/config/database.php write the following:-

class DATABASE_CONFIG {

var $default = array(

'driver'                => 'mysql',

'host'                  => 'slave.host.ip',

'login'                 => '....',

'password'              => '.....',

'database'              => 'my_db'

);

var $master = array(

'driver'                => 'mysql',

'host'                  => 'master.host.ip',

'login'                 => '....',

'password'              => '.....',

'database'              => 'my_db'

);

}

Then, in app/app_model.php, create 4 new methods:

function beforeSave() {

$this->useDbConfig = 'master';

return true;

}

function afterSave() {

$this->useDbConfig = 'default';

return true;

}

function beforeDelete() {

$this->useDbConfig = 'master';

return true;

}

function afterDelete() {

$this->useDbConfig = 'default';

return true;

}

It really is as simple as that.

However, there are some instance where you may want to use a query in your controller where you update/insert information. In this case, use the following:

$this->ModelName->setDataSource('master');

$this->ModelName->query("UPDATE post_views SET views=views+1 WHERE id=1234");

$this->ModelName->setDataSource('default');

I use this where I want information to be updated, but don't want cake to flush the cache. But then again, that may be like crossing the streams in Ghostbusters, so don't listen to me..

With thanks to Nate and gwoo

http://www.howtoforge.com/mysql_master_master_replication