Owen Conti

Improving the Performance of your Laravel Queue

January 12, 2019 - ⌚ ~2 minutes to read


Out of the box, Laravel has a great API for dispatching jobs:

ProcessPodcast::dispatch($podcast);

☝ That will dispatch the ProcessPodcast job, with the $podcast being passed in for the job to use as it wants.

Under the hood, Laravel is doing the following:

  • Detects an Eloquent Model was passed into the job
  • If the job uses the SerializesModels trait, the identifer of the passed Model is serialized as the payload of the job
  • When the queue processes the job, Laravel unserializes the ID, loads the Model from the database, and passes it to the job

This all works very well and makes using Laravel’s Queue system a breeze!

🚨🚨 There’s a catch! 🚨🚨

Laravel is trying to be extra helpful by also serializing the loaded relations, and then eagerly loads them when the job is processed.

So let’s say in order to dispatch the ProcessPodcast job, you have to load 5 relations on the Podcast model. When the ProcessPodcast job is processed from the queue, all 5 of those relations (and any of their loaded nested relations) are eagerly loaded.

Depending on your application and the logic of your job, this may make a significant impact on your queue’s processing time.

What’s the fix?

If your job needs to use the relations to dispatch the job, but does not need those relations when processing the job, you can instead pass the identifier of the model instead of the model itself. It’s a little bit more work on your end, because you’ll be responsible for pulling the model out of the database on your own, but it also gives you more control.

Now when dispatching your job, you can do this:

ProcessPodcast::dispatch($podcast->id);

And inside your job’s class:

public function __construct(int $podcastId)
{
    $this->podcastId = $podcastId;
}

public function handle()
{
    $podcast = Podcast::findOrFail($this->podcastId);
}

In the application I found this issue on, the processing time of one of our jobs went from ~8 seconds down to ~1 second.

Tags: laravel php tips performance 

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