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. To use this, you will need to:

  1. Register a MongoDbSessionHandler service;
  2. Configure this under framework.session.handler_id configuration.

To see how to configure a similar handler, see How to Use PdoSessionHandler to Store Sessions in the Database.

Setting Up the MongoDB Collection

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 } )