The Laravel Queue component provides a unified API across a variety of different queue services. Queues allow you to defer the processing of a time consuming task, such as sending an e-mail, until a later time, thus drastically speeding up the web requests to your application.
The queue configuration file is stored in app/config/queue.php. In this file you will find connection configurations for each of the queue drivers that are included with the framework, which includes a Beanstalkd, IronMQ, Amazon SQS, and synchronous (for local use) driver.
The following dependencies are needed for the listed queue drivers:
- Beanstalkd:
pda/pheanstalk - Amazon SQS:
aws/aws-sdk-php - IronMQ:
iron-io/iron_mq
To push a new job onto the queue, use the Queue::push method:
Pushing A Job Onto The Queue
Queue::push('SendEmail', array('message' => $message));
The first argument given to the push method is the name of the class that should be used to process the job. The second argument is an array of data that should be passed to the handler. A job handler should be defined like so:
Defining A Job Handler
class SendEmail {
public function fire($job, $data)
{
//
}
}
Notice the only method that is required is fire, which receives a Job instance as well as the array of data that was pushed onto the queue.
If you want the job to use a method other than fire, you may specify the method when you push the job:
Specifying A Custom Handler Method
Queue::push('SendEmail@send', array('message' => $message));
Once you have processed a job, it must be deleted from the queue, which can be done via the delete method on the Job instance:
Deleting A Processed Job
public function fire($job, $data)
{
// Process the job...
$job->delete();
}
If you wish to release a job back onto the queue, you may do so via the release method:
Releasing A Job Back Onto The Queue
public function fire($job, $data)
{
// Process the job...
$job->release();
}
You may also specify the number of seconds to wait before the job is released:
$job->release(5);
If an exception occurs while the job is being processed, it will automatically be released back onto the queue. You may check the number of attempts that have been made to run the job using the attempts method:
Checking The Number Of Run Attempts
if ($job->attempts() > 3)
{
//
}
You may also access the job identifier:
Accessing The Job ID
$job->getJobId();
You may also push a Closure onto the queue. This is very convenient for quick, simple tasks that need to be queued:
Pushing A Closure Onto The Queue
Queue::push(function($job) use ($id)
{
Account::delete($id);
$job->delete();
});
Note: When pushing Closures onto the queue, the
__DIR__and__FILE__constants should not be used.
When using Iron.io push queues, you should take extra precaution queueing Closures. The end-point that receives your queue messages should check for a token to verify that the request is actually from Iron.io. For example, your push queue end-point should be something like: https://yourapp.com/queue/receive?token=SecretToken. You may then check the value of the secret token in your application before marshaling the queue request.
Laravel includes an Artisan task that will run new jobs as they are pushed onto the queue. You may run this task using the queue:listen command:
Starting The Queue Listener
php artisan queue:listen
You may also specify which queue connection the listener should utilize:
php artisan queue:listen connection
Note that once this task has started, it will continue to run until it is manually stopped. You may use a process monitor such as Supervisor to ensure that the queue listener does not stop running.
You may also set the length of time (in seconds) each job should be allowed to run:
Specifying The Job Timeout Parameter
php artisan queue:listen --timeout=60
To process only the first job on the queue, you may use the queue:work command:
Processing The First Job On The Queue
php artisan queue:work
Push queues allow you to utilize the powerful Laravel 4 queue facilities without running any daemons or background listeners. Currently, push queues are only supported by the Iron.io driver. Before getting started, create an Iron.io account, and add your Iron credentials to the app/config/queue.php configuration file.
Next, you may use the queue:subscribe Artisan command to register a URL end-point that will receive newly pushed queue jobs:
Registering A Push Queue Subscriber
php artisan queue:subscribe queue_name http://foo.com/queue/receive
Now, when you login to your Iron dashboard, you will see your new push queue, as well as the subscribed URL. You may subscribe as many URLs as you wish to a given queue. Next, create a route for your queue/receive end-point and return the response from the Queue::marshal method:
Route::post('queue/receive', function()
{
return Queue::marshal();
});
The marshal method will take care of firing the correct job handler class. To fire jobs onto the push queue, just use the same Queue::push method used for conventional queues.