How to Use MongoDbSessionHandler to Store Sessions in a MongoDB Database

How to Use MongoDbSessionHandler to Store Sessions in a MongoDB Database

The default Symfony session storage writes the session information to files. Some medium to large websites use a NoSQL database called MongoDB to store the session values instead of files, because databases are easier to use and scale in a multi-webserver environment.

Symfony has a built-in solution for NoSQL database session storage called MongoDbSessionHandler. MongoDB is an open-source document database that provides high performance, high availability and automatic scaling. This article assumes that you have already installed and configured a MongoDB server. To use it, you just need to change/add some parameters in the main configuration file:

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    # app/config/config.yml
    framework:
        session:
            # ...
            handler_id:  session.handler.mongo
            cookie_lifetime: 2592000 # optional, it is set to 30 days here
            gc_maxlifetime: 2592000 # optional, it is set to 30 days here
    
    services:
        # ...
        mongo_client:
            class: MongoClient
            # if using a username and password
            arguments: ['mongodb://%mongodb_username%:%mongodb_password%@%mongodb_host%:27017']
            # if not using a username and password
            arguments: ['mongodb://%mongodb_host%:27017']
        session.handler.mongo:
            class: Symfony\Component\HttpFoundation\Session\Storage\Handler\MongoDbSessionHandler
            arguments: ['@mongo_client', '%mongo.session.options%']
    
  • XML
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    <?xml version="1.0" encoding="UTF-8"?>
    <container xmlns="http://symfony.com/schema/dic/services"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-Instance"
        xmlns:framework="http://symfony.com/schema/dic/symfony"
        xsi:schemaLocation="http://symfony.com/schema/dic/services
            http://symfony.com/schema/dic/services/services-1.0.xsd
            http://symfony.com/schema/dic/symfony
            http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
    
        <framework:config>
            <!-- ... -->
    
            <!-- cookie-lifetime and gc-maxlifetime are optional and set to
                 30 days in this example -->
            <framework:session handler-id="session.handler.mongo"
                cookie-lifetime="2592000"
                gc-maxlifetime="2592000"
            />
        </framework:config>
    
        <services>
            <service id="mongo_client" class="MongoClient">
                <!-- if using a username and password -->
                <argument>mongodb://%mongodb_username%:%mongodb_password%@%mongodb_host%:27017</argument>
    
                <!-- if not using a username and password -->
                <argument>mongodb://%mongodb_host%:27017</argument>
            </service>
    
            <service id="session.handler.mongo" class="Symfony\Component\HttpFoundation\Session\Storage\Handler\MongoDbSessionHandler">
                <argument type="service">mongo_client</argument>
                <argument>%mongo.session.options%</argument>
            </service>
    </container>
    
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    use Symfony\Component\DependencyInjection\Reference;
    use Symfony\Component\HttpFoundation\Session\Storage\Handler\MongoDbSessionHandler;
    
    $container->loadFromExtension('framework', array(
        'session' => array(
            // ...
            'handler_id'      => 'session.handler.mongo',
            'cookie_lifetime' => 2592000, // optional, it is set to 30 days here
            'gc_maxlifetime'  => 2592000, // optional, it is set to 30 days here
        ),
    ));
    
    $container->register('mongo_client', \MongoClient::class)
        ->setArguments(array(
            // if using a username and password
            array('mongodb://%mongodb_username%:%mongodb_password%@%mongodb_host%:27017'),
            // if not using a username and password
            array('mongodb://%mongodb_host%:27017'),
        ));
    
    $container->register('session.handler.mongo', MongoDbSessionHandler::class)
        ->setArguments(array(
            new Reference('mongo_client'),
            '%mongo.session.options%',
        ));
    

The parameters used above should be defined somewhere in your application, often in your main parameters configuration:

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    # app/config/parameters.yml
    parameters:
        # ...
        mongo.session.options:
            database: session_db # your MongoDB database name
            collection: session  # your MongoDB collection name
        mongodb_host: 1.2.3.4 # your MongoDB server's IP
        mongodb_username: my_username
        mongodb_password: my_password
    
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    <?xml version="1.0" encoding="UTF-8"?>
    <container xmlns="http://symfony.com/schema/dic/services"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-Instance"
        xmlns:framework="http://symfony.com/schema/dic/symfony"
        xsi:schemaLocation="http://symfony.com/schema/dic/services
            http://symfony.com/schema/dic/services/services-1.0.xsd
            http://symfony.com/schema/dic/symfony
            http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
    
        <parameters>
            <parameter key="mongo.session.options" type="collection">
                <!-- your MongoDB database name -->
                <parameter key="database">session_db</parameter>
                <!-- your MongoDB collection name -->
                <parameter key="collection">session</parameter>
            </parameter>
            <!-- your MongoDB server's IP -->
            <parameter key="mongodb_host">1.2.3.4</parameter>
            <parameter key="mongodb_username">my_username</parameter>
            <parameter key="mongodb_password">my_password</parameter>
        </parameters>
    </container>
    
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    use Symfony\Component\DependencyInjection\Reference;
    
    $container->setParameter('mongo.session.options', array(
        'database'   => 'session_db', // your MongoDB database name
        'collection' => 'session',  // your MongoDB collection name
    ));
    $container->setParameter('mongodb_host', '1.2.3.4'); // your MongoDB server's IP
    $container->setParameter('mongodb_username', 'my_username');
    $container->setParameter('mongodb_password', 'my_password');
    

Setting Up the MongoDB Collection

Because MongoDB uses dynamic collection schemas, you do not need to do anything to initialize your session collection. However, you may want to add an index to improve garbage collection performance. From the MongoDB shell:

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use session_db
db.session.ensureIndex( { "expires_at": 1 }, { expireAfterSeconds: 0 } )

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.