public function diDbSlave()
{
$config = $this->getDI()->getConfig();
$slaves = $config->dbAdapter->slave;
$slaveKey = array_rand($slaves->toArray());
if (!isset($slaves->{$slaveKey}) || count($slaves) < 1) {
throw new Exception\RuntimeException(sprintf('No DB slave options found'));
}
return $this->diDbAdapter($slaves->{$slaveKey}->adapter, $slaves->{$slaveKey}->toArray(), $this->getDI());
}