Queue

If you're just starting out, you won't need a queue. But once you reach a certain scale, you cannot go without one.

Why should I care?

A Flarum installation that has no queue configured, will process a wide variety of tasks during the request of a user. The best example of such a task are email notifications. Flarum Subscriptions, Friends of Flarum Follow Tags and IanM Follow Users are just a few extensions that trigger email notifications for new activity. It is probably not a mystery that having a community of ten users will not be much of an issue in this regard. However once you have thousands it is far more likely that these notifications will take a long time, and affect the interaction of users on your community.

To resolve this increasing burden, you can run a Queue. A queue runs on your server, it does not interact with the user and their requests. A user request, however, can dispatch tasks to the queue.

By default, Flarum uses the sync driver, which processes jobs immediately inline during the user's request — convenient, but it means the user waits for every job to complete before getting a response.

How do I set up a queue?

Since Flarum 2.x, the database queue driver is built into Flarum core — no additional extension is required. To enable it, set the queue driver to database in your config.php:

'queue' => [
    'driver' => 'database',
],

The database queue re-uses the scheduler to process jobs, so you must have the scheduler configured to run every minute for it to work. See the scheduler guide for setup instructions.

For more advanced queue solutions (e.g. Redis-backed queues), extensions such as FoF Redis are available.