config.yml

# Symfony Doctrine MongoDB Configuration
doctrine_mongodb:
    connections:
        default:
            server: %mongodb_server%
            options:
                connect: true
    default_database: %mongodb_database%_%kernel.environment%
    document_managers:
        default:
            auto_mapping: true
            logging: true
            metadata_cache_driver:
                type: array

Example.php

<?php

$this->storageManager
     ->getRepository('PlemiAuthServerBundle:Client')
     ->find($authCode->getClientId());

$this->storageManager
     ->getRepository('PlemiAuthServerBundle:Client')
     ->find($authCode->getClientId());

$this->storageManager
     ->getRepository('PlemiAuthServerBundle:Client')
     ->find($authCode->getClientId());

$this->storageManager
     ->getRepository('PlemiAuthServerBundle:Client')
     ->find($authCode->getClientId());