<?php
class Rediska_Zend_Application_Resource_Rediska extends
      Zend_Application_Resource_ResourceAbstract
{
    public function init()
    {
        return $this->getOptions();
    }
}

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

<?php
$paths = array(
    '/path_one/',
    '/path_two/'
);
set_include_path(implode(PATH_SEPARATOR, $paths));
require_once 'Zend/Loader/Autoloader.php';
Zend_Loader_Autoloader::getInstance();

$options = array(
    'pluginpaths' => array(
        'Rediska_Zend_Application_Resource' => 'Rediska/Zend/Application/Resource'),
    'resources' => array(
        'rediska' => array(
            'namespace' => 'Rediska_Test_',
            'servers' => array(
                array('host' => '127.0.0.1', 'port' => '6379')
            ),
        )
    )
);

class Rediska
{

}

$application = new Zend_Application('tests', $options);
$rediska = $application->bootstrap()->getBootstrap()->getResource('rediska');
var_dump($rediska);