[LARAVEL HORIZON] How to specify which Queue Connection Laravel Horizon uses

@tr8norman you can do this using the onConnection function.

MyJob::dispatch(); // will dispatch to default connection

//you should:
MyJob::onConnection('redis_a')->dispatch();
//or
MyJob::onConnection('redis_b')->dispatch();
// to dispatch on specific connections

On your database.php https://github.com/laravel/laravel/blob/8.x/config/database.php#L129 you should have the following:

'redis' => [
		...
        'redis_a' => [
            'url' => env('REDIS_URL'),
            'host' => env('REDIS_HOST', '127.0.0.1'),
            'password' => env('REDIS_PASSWORD', null),
            'port' => env('REDIS_PORT', '6379'),
            'database' => env('REDIS_DB', '0'),
        ],
        'redis_b' => [
            'url' => env('REDIS_URL'),
            'host' => env('REDIS_HOST', '127.0.0.1'),
            'password' => env('REDIS_PASSWORD', null),
            'port' => env('REDIS_PORT', '6379'),
            'database' => env('REDIS_DB', '0'),
        ],
		...
]

Of course, change it to your true credentials but you get the point.

And to have your redis_a becomes the default driver, change default to redis_a: https://github.com/laravel/laravel/blob/8.x/config/queue.php#L67

Then make sure you clear your configs :)

I noticed that I can still see jobs that I submitted to Redis B in Pending jobs of horizon of Application X Since you didn't define where you should dispatch your jobs, you dispatched all your jobs to the default connection.

Hi @neilstee

I have another question related to this and I hope that you can help.

If I understand correctly for use, the explanation given in the config file is

This is the name of the Redis connection where Horizon will store the
    | meta information required for it to function. It includes the list
    | of supervisors, failed jobs, job metrics, and other information.

So this is actually not related to which Redis queue connection Horizon is listening to.

My hunch is that Horizon monitors job submitted to any Redis connections since Horizon basically overrides RedisQueue implementation which will be used regardless which Redis connection is used.

So in the case that an Application has 2 different Redis Connection (each have different Queue, Queue A and Queue B respectively), Horizon actually monitors jobs submitted to both Redis Connection.

Can you clarify if this is the case?

@tr8norman

So this is actually not related to which Redis queue connection Horizon is listening to.

No, it will only get the jobs to that particular connection.

My hunch is that Horizon monitors job submitted to any Redis connections since Horizon basically overrides RedisQueue implementation which will be used regardless which Redis connection is used.

No, UNLESS you didn't configure connections to have different prefixes. https://github.com/laravel/laravel/blob/8.x/config/database.php#L126

Basically, you need to move that prefix key inside the default key or your new connection.

So in the case that an Application has 2 different Redis Connection (each have different Queue, Queue A and Queue B respectively), Horizon actually monitors jobs submitted to both Redis Connection.

No, as well.

You can understand the Redis prefix here more: https://laracasts.com/series/build-and-configure-a-staging-server/episodes/5