Laravel queue rate limiting or throttling

I'm the author of mxl/laravel-queue-rate-limit Composer package.

It allows you to rate limit jobs on specific queue without using Redis.

1. Install it with:

   $ composer require mxl/laravel-queue-rate-limit:^1.0

2. This package is compatible with Laravel 5.5+ and uses auto-discovery feature to add MichaelLedin\LaravelQueueRateLimit\QueueServiceProvider::class to providers.

3. Add rate limit settings to config/queue.php:

   'rateLimit' => [    'mail' => [        'allows' => 1,        'every' => 5    ]]

   These settings allow to run 1 job every 5 seconds on mail queue.Make sure that default queue driver (default property in config/queue.php) is set to any value except sync.

4. Run queue worker with --queue mail option:

   $ php artisan queue:work --queue mail

   You can run worker on multiple queues, but only queues referenced in rateLimit setting will be rate limited:

   $ php artisan qeueu:work --queue mail,default

   Jobs on default queue will be executed without rate limiting.

5. Queue some jobs to test rate limiting:

   SomeJob::dispatch()->onQueue('mail');SomeJob::dispatch()->onQueue('mail');SomeJob::dispatch()->onQueue('mail');SomeJob::dispatch();

Assuming you have only single worker you can do something like this:

• do what has to be done
• get time (with microseconds)
• sleep time that is 1s minus difference between finish time and start time

so basically:

doSomething()$time = microtime(true);usleep(1000 - ($time - LARAVEL_START));

If you need "throttling" and are not using Redis as your queue driver you can try to use the following code:

public function throttledJobDispatch( $delayInSeconds = 1 ) {   $lastJobDispatched = Cache::get('lastJobDispatched');   if( !$lastJobDispatched ) {      $delay_until = now();   } else {       if ($lastJobDispatched->addSeconds($delayInSeconds) < now()) {         $delay_until = now();      } else {         $delay_until = $lastJobDispatched->addSeconds($delayInSeconds);      }   }   Job::dispatch()->onQueue('YourQueue')->delay($delay_until);   Cache::put('lastJobDispatched', $delay_until, now()->addYears(1) );}

What this code does is release a job to the queue and set the start time X seconds after the last dispatched job's start time. I successully tested this with database as queue-driver and file as cache driver.

There are two minor problems I have encountered so far:

1) When you use only 1 second as a delay, depending on your queue worker - the queue worker may actually only "wake up" once every couple of seconds. So, if it wakes up every 3 seconds, it will perform 3 jobs at once and then "sleep" 3 seconds again. But on average you will still only perform one job every second.

2) In Laravel 5.7 it is not possible to use Carbon to set the job delay to less than a second because it does not support milli- or microseconds yet. That should be possible with Laravel 5.8 - just use addMilliseconds instead of addSeconds.