thm-health/pilos/configuring-horizon

Horizon Configuration

Documentation

Use search-docs for detailed Horizon patterns and documentation covering configuration, supervisors, balancing, dashboard authorization, tags, notifications, metrics, and deployment.

For deeper guidance on specific topics, read the relevant reference file before implementing:

• references/supervisors.md covers supervisor blocks, balancing strategies, multi-queue setups, and auto-scaling
• references/notifications.md covers LongWaitDetected alerts, notification routing, and the waits config
• references/tags.md covers job tagging, dashboard filtering, and silencing noisy jobs
• references/metrics.md covers the blank metrics dashboard, snapshot scheduling, and retention config

Basic Usage

Installation

vendor/bin/sail artisan horizon:install

Supervisor Configuration

Define supervisors in config/horizon.php. The environments array merges into defaults and does not replace the whole supervisor block:

<!-- Supervisor Config -->

'defaults' => [
    'supervisor-1' => [
        'connection' => 'redis',
        'queue' => ['default'],
        'balance' => 'auto',
        'minProcesses' => 1,
        'maxProcesses' => 10,
        'tries' => 3,
    ],
],
 
'environments' => [
    'production' => [
        'supervisor-1' => ['maxProcesses' => 20, 'balanceCooldown' => 3],
    ],
    'local' => [
        'supervisor-1' => ['maxProcesses' => 2],
    ],
],

Dashboard Authorization

Restrict access in App\Providers\HorizonServiceProvider:

<!-- Dashboard Gate -->

protected function gate(): void
{
    Gate::define('viewHorizon', function (User $user) {
        return $user->is_admin;
    });
}

Verification

1. Run vendor/bin/sail artisan horizon and visit /horizon
2. Confirm dashboard access is restricted as expected
3. Check that metrics populate after scheduling horizon:snapshot

Common Pitfalls

• Horizon only works with the Redis queue driver. Other drivers such as database and SQS are not supported.
• Redis Cluster is not supported. Horizon requires a standalone Redis connection.
• Always check config/horizon.php before making changes to understand the current supervisor and environment configuration.
• The environments array overrides only the keys you specify. It merges into defaults and does not replace it.
• The timeout chain must be ordered: job timeout less than supervisor timeout less than retry_after. The wrong order can cause jobs to be retried before Horizon finishes timing them out.
• The metrics dashboard stays blank until horizon:snapshot is scheduled. Running vendor/bin/sail artisan horizon alone does not populate metrics.
• Always use search-docs for the latest Horizon documentation rather than relying on this skill alone.