TopolearnSending email, calling APIs and processing files in the request makes apps slow and fragile; queues fix that.
A job is a class representing work to do later: php artisan make:job ProcessPodcast. It implements ShouldQueue and has a handle() method, whose dependencies are injected by the container.
Dispatch it with ProcessPodcast::dispatch($podcast). The job is serialised and stored by the queue driver: database (the default in new apps), redis, sqs, beanstalkd, or sync (runs immediately, handy for tests). A worker process picks jobs up: php artisan queue:work. In production, keep workers alive with Supervisor or systemd, and restart them on deploy with php artisan queue:restart, since they keep old code in memory.
Models passed to a job are stored as identifiers (thanks to SerializesModels) and re-fetched fresh when the job runs.
Reliability controls:
public $tries = 5;andpublic $backoff = [10, 60, 300];for retries;retryUntil()for a deadline;$timeoutfor runaway jobs.failed(Throwable $e)runs after the final failure; failed jobs land in thefailed_jobstable (queue:failed,queue:retry all).- Make jobs idempotent, since a job can run more than once.
Dispatching inside a database transaction is risky: the worker may run before the commit and not find the row. Use ->afterCommit() or the after_commit connection option.
Extras: ->delay(now()->addMinutes(10)), ->onQueue('emails'), Bus::chain([...]) for sequences, Bus::batch([...]) for groups with progress and callbacks, ShouldBeUnique and rate-limiting middleware. Horizon gives Redis queues a dashboard and auto-balancing.
Example
<?php
// app/Jobs/GenerateInvoicePdf.php
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Queue\Queueable;
class GenerateInvoicePdf implements ShouldQueue
{
use Queueable;
public int $tries = 4;
public array $backoff = [10, 60, 300]; // seconds between attempts
public function __construct(public Invoice $invoice) {} // stored as an id
public function handle(PdfRenderer $pdf): void // injected
{
if ($this->invoice->pdf_path) return; // idempotent
$path = $pdf->render('invoices.show', ['invoice' => $this->invoice]);
$this->invoice->update(['pdf_path' => $path]);
}
public function failed(Throwable $e): void
{
$this->invoice->owner->notify(new InvoiceFailed($this->invoice));
}
}
// Controller: respond fast, work later (after the transaction commits)
GenerateInvoicePdf::dispatch($invoice)->onQueue('pdfs')->afterCommit();
// $ php artisan queue:work --queue=pdfs,default --tries=4Remember
- Jobs implement ShouldQueue and are processed by queue:work workers
- Configure tries, backoff and failed(); design jobs to be idempotent
- Dispatch after commit and restart workers on deploy
Watch out for
- Deploying new code without queue:restart, so long-running workers keep executing the old version.