Resque is a Redis-backed library for creating background jobs, placing those jobs on one or more queues, and processing them later.
This is a PHP fork of the Resque worker and job classes. This makes it compatible with the resque-web interface, and with other Resque libraries. (You could enqueue jobs from Ruby and dequeue them in PHP, for instance).
This library (vend/resque
) is a fork of chrisboulton/php-resque at around
version 1.3, that has been refactored to remove global state, add namespacing, and improve
decoupling. This makes it easier to use and extend.
Add vend/resque
to your application's composer.json.
{
"require": {
"vend/resque": "~2.1.0"
}
}
Jobs are queued as follows:
use Resque\Resque;
use Predis\Client;
$resque = new Resque(new Client());
$resque->enqueue('default_queue', 'App\Job', array('foo' => 'bar'), true);
In order the arguments are: queue, job class, job payload, whether to enable tracking.
Each job should be in its own class, and implement the Resque\JobInterface
. (This is pretty easy,
and only really requires a single custom method: perform()
.) Most of the time, you'll want to
use the default implementation of a Job, and extend the Resque\AbstractJob
instead of implementing
the interface yourself:
namespace App;
use Resque\AbstractJob;
class Job extends AbstractJob
{
public function perform()
{
// work work work
$this->doSomething($this->payload['foo']);
}
}
Any exception thrown by a job will result in the job failing - be careful here and make sure you handle the exceptions that shouldn't result in a job failing.
vend/resque has the ability to perform basic status tracking of a queued job. The status information will allow you to check if a job is in the queue, is currently being run, has finished, or has failed.
To track the status of a job, pass true
as the fourth argument to
Resque\Resque::enqueue
. An ID used for tracking the job status will be
returned:
$id = $resque->enqueue('default_queue', 'App\Job', $payload, true);
echo $id; // [0-9a-f]{32}
To fetch the status of a job:
$factory = new Resque\Job\StatusFactory($resque);
// Pass the ID returned from enqueue
$status = $factory->forId($id);
// Alternatively, to get the status for a Job instance:
$status = $factory->forJob($job);
// Outputs the status as a string: 'waiting', 'running', 'complete', etc.
echo $status->getStatus();
The Status object contains methods for adding other attributes to the tracked status. (For instance, you might use the status object to track errors, completion information, iterations, etc.)
Job statuses are defined as constants in the Resque\Job\Status
class.
Valid statuses include:
Resque\Job\Status::STATUS_WAITING
- Job is still queuedResque\Job\Status::STATUS_RUNNING
- Job is currently runningResque\Job\Status::STATUS_FAILED
- Job has failedResque\Job\Status::STATUS_COMPLETE
- Job is completeStatuses are available for up to 24 hours after a job has completed
or failed, and are then automatically expired. A status can also
forcefully be expired by calling the stop()
method on a status
class.
You are free you implement your own daemonization/worker pool strategy by
subclassing the Worker
class. For playing around, and low throughput
applications, you might like to use the built-in console commands.
This version of the library uses the Symfony2 Console component. But it
must be configured with the details of your Redis connection. We do this
in much the same way that the Doctrine2 Console component gets details
of your database connection: via a cli-config.php
file.
There is an example cli-config.php
in this repository.
If you're running a full-stack web application, you'd generally use your locator/service container to fill in the Redis client connection in this file. (The default is to use Predis, and to connect to 127.0.0.1:6379).
resque <subcommand>
Available commands:
enqueue Enqueues a job into a queue
help Displays help for a command
list Lists commands
worker Runs a Resque worker
queue
queue:clear Clears a specified queue
queue:list Outputs information about queues
This command will enqueue a Some\Test\Job
job onto the default
queue.
Watch out for the single quotes around the class name: when specifying backslashes
on the command line, you'll probably have to avoid your shell escaping them.
resque enqueue default 'Some\Test\Job' -t
This command will run a simple pre-forking worker on two queues:
resque worker -Q default -Q some_other_queue
(-q
means quiet, -Q
specifies queues). You can also specify no queues, or
the special queue '*'
(watch for shell expansion).
There are a couple of useful commands for getting information about the queues. This will show a list of queues and how many jobs are waiting on each:
resque queue:list
This command will clear a specified queue:
resque queue:clear default
The library now uses PSR3. When running as a console component, you can customise
the logger to use in cli-config.php
. (For instance, you might like to send your
worker logs to Monolog.)
Unfortunately, several things about the existing versions of php-resque made it a candidate for refactoring:
php-resque
was alright, the protected API was pretty
much useless. This made it hard to extend worker classes to dispatch jobs differently.Resque::redis()
). This makes things
easier for the library author (because he/she need not think about dependencies)
but also statically ties together the classes in the library: it makes
testing and extending the library hard.
Resque
instances should simply use DI and
take a client connection as a required constructor argument.Resque
class.Resque_Stat
class was hard-coded into
several other classes, and could not be easily extended.Resque
.Here's the contributor list from earlier versions, at chrisboulton/php-resque: