Laravel 8.x Task Scheduling

Introduction

In the past, you may have written a cron configuration entry for each task you needed to schedule on your server. However, this can quickly become a pain because your task schedule is no longer in source control and you must SSH into your server to view your existing cron entries or add additional entries.

Laravel's command scheduler offers a fresh approach to managing scheduled tasks on your server. The scheduler allows you to fluently and expressively define your command schedule within your Laravel application itself. When using the scheduler, only a single cron entry is needed on your server. Your task schedule is defined in the app/Console/Kernel.php file's schedule method. To help you get started, a simple example is defined within the method.

Defining Schedules

You may define all of your scheduled tasks in the schedule method of your application's App\Console\Kernel class. To get started, let's take a look at an example. In this example, we will schedule a closure to be called every day at midnight. Within the closure we will execute a database query to clear a table:

<?php

namespace App\Console;

use Illuminate\Console\Scheduling\Schedule;
use Illuminate\Foundation\Console\Kernel as ConsoleKernel;
use Illuminate\Support\Facades\DB;

class Kernel extends ConsoleKernel
{
    /**
     * Define the application's command schedule.
     *
     * @param  \Illuminate\Console\Scheduling\Schedule  $schedule
     * @return void
     */
    protected function schedule(Schedule $schedule)
    {
        $schedule->call(function () {
            DB::table('recent_users')->delete();
        })->daily();
    }
}

In addition to scheduling using closures, you may also schedule invokable objects. Invokable objects are simple PHP classes that contain an __invoke method:

$schedule->call(new DeleteRecentUsers)->daily();

If you would like to view an overview of your scheduled tasks and the next time they are scheduled to run, you may use the schedule:list Artisan command:

php artisan schedule:list

Scheduling Artisan Commands

In addition to scheduling closures, you may also schedule Artisan commands and system commands. For example, you may use the command method to schedule an Artisan command using either the command's name or class.

When scheduling Artisan commands using the command's class name, you may pass an array of additional command-line arguments that should be provided to the command when it is invoked:

use App\Console\Commands\SendEmailsCommand;

$schedule->command('emails:send Taylor --force')->daily();

$schedule->command(SendEmailsCommand::class, ['Taylor', '--force'])->daily();

Scheduling Queued Jobs

The job method may be used to schedule a queued job. This method provides a convenient way to schedule queued jobs without using the call method to define closures to queue the job:

use App\Jobs\Heartbeat;

$schedule->job(new Heartbeat)->everyFiveMinutes();

Optional second and third arguments may be provided to the job method which specifies the queue name and queue connection that should be used to queue the job:

use App\Jobs\Heartbeat;

// Dispatch the job to the "heartbeats" queue on the "sqs" connection...
$schedule->job(new Heartbeat, 'heartbeats', 'sqs')->everyFiveMinutes();

Scheduling Shell Commands

The exec method may be used to issue a command to the operating system:

$schedule->exec('node /home/forge/script.js')->daily();

Schedule Frequency Options

We've already seen a few examples of how you may configure a task to run at specified intervals. However, there are many more task schedule frequencies that you may assign to a task:

These methods may be combined with additional constraints to create even more finely tuned schedules that only run on certain days of the week. For example, you may schedule a command to run weekly on Monday:

// Run once per week on Monday at 1 PM...
$schedule->call(function () {
    //
})->weekly()->mondays()->at('13:00');

// Run hourly from 8 AM to 5 PM on weekdays...
$schedule->command('foo')
          ->weekdays()
          ->hourly()
          ->timezone('America/Chicago')
          ->between('8:00', '17:00');

A list of additional schedule constraints may be found below:

Day Constraints

The days method may be used to limit the execution of a task to specific days of the week. For example, you may schedule a command to run hourly on Sundays and Wednesdays:

$schedule->command('emails:send')
                ->hourly()
                ->days([0, 3]);

Alternatively, you may use the constants available on the Illuminate\Console\Scheduling\Schedule class when defining the days on which a task should run:

use Illuminate\Console\Scheduling\Schedule;

$schedule->command('emails:send')
                ->hourly()
                ->days([Schedule::SUNDAY, Schedule::WEDNESDAY]);

Between Time Constraints

The between method may be used to limit the execution of a task based on the time of day:

$schedule->command('emails:send')
                    ->hourly()
                    ->between('7:00', '22:00');

Similarly, the unlessBetween method can be used to exclude the execution of a task for a period of time:

$schedule->command('emails:send')
                    ->hourly()
                    ->unlessBetween('23:00', '4:00');

Truth Test Constraints

The when method may be used to limit the execution of a task based on the result of a given truth test. In other words, if the given closure returns true, the task will execute as long as no other constraining conditions prevent the task from running:

$schedule->command('emails:send')->daily()->when(function () {
    return true;
});

The skip method may be seen as the inverse of when. If the skip method returns true, the scheduled task will not be executed:

$schedule->command('emails:send')->daily()->skip(function () {
    return true;
});

When using chained when methods, the scheduled command will only execute if all when conditions return true.

Environment Constraints

The environments method may be used to execute tasks only on the given environments (as defined by the APP_ENV environment variable):

$schedule->command('emails:send')
            ->daily()
            ->environments(['staging', 'production']);

Timezones

Using the timezone method, you may specify that a scheduled task's time should be interpreted within a given timezone:

$schedule->command('report:generate')
         ->timezone('America/New_York')
         ->at('2:00')

If you are repeatedly assigning the same timezone to all of your scheduled tasks, you may wish to define a scheduleTimezone method in your App\Console\Kernel class. This method should return the default timezone that should be assigned to all scheduled tasks:

/**
 * Get the timezone that should be used by default for scheduled events.
 *
 * @return \DateTimeZone|string|null
 */
protected function scheduleTimezone()
{
    return 'America/Chicago';
}

Note: note Remember that some timezones utilize daylight savings time. When daylight saving time changes occur, your scheduled task may run twice or even not run at all. For this reason, we recommend avoiding timezone scheduling when possible.

Preventing Task Overlaps

By default, scheduled tasks will be run even if the previous instance of the task is still running. To prevent this, you may use the withoutOverlapping method:

$schedule->command('emails:send')->withoutOverlapping();

In this example, the emails:send Artisan command will be run every minute if it is not already running. The withoutOverlapping method is especially useful if you have tasks that vary drastically in their execution time, preventing you from predicting exactly how long a given task will take.

If needed, you may specify how many minutes must pass before the "without overlapping" lock expires. By default, the lock will expire after 24 hours:

$schedule->command('emails:send')->withoutOverlapping(10);

Running Tasks On One Server

Note: note To utilize this feature, your application must be using the database, memcached, dynamodb, or redis cache driver as your application's default cache driver. In addition, all servers must be communicating with the same central cache server.

If your application's scheduler is running on multiple servers, you may limit a scheduled job to only execute on a single server. For instance, assume you have a scheduled task that generates a new report every Friday night. If the task scheduler is running on three worker servers, the scheduled task will run on all three servers and generate the report three times. Not good!

To indicate that the task should run on only one server, use the onOneServer method when defining the scheduled task. The first server to obtain the task will secure an atomic lock on the job to prevent other servers from running the same task at the same time:

$schedule->command('report:generate')
                ->fridays()
                ->at('17:00')
                ->onOneServer();

Background Tasks

By default, multiple tasks scheduled at the same time will execute sequentially based on the order they are defined in your schedule method. If you have long-running tasks, this may cause subsequent tasks to start much later than anticipated. If you would like to run tasks in the background so that they may all run simultaneously, you may use the runInBackground method:

$schedule->command('analytics:report')
         ->daily()
         ->runInBackground();

Note: note The runInBackground method may only be used when scheduling tasks via the command and exec methods.

Maintenance Mode

Your application's scheduled tasks will not run when the application is in maintenance mode, since we don't want your tasks to interfere with any unfinished maintenance you may be performing on your server. However, if you would like to force a task to run even in maintenance mode, you may call the evenInMaintenanceMode method when defining the task:

$schedule->command('emails:send')->evenInMaintenanceMode();

Running The Scheduler

Now that we have learned how to define scheduled tasks, let's discuss how to actually run them on our server. The schedule:run Artisan command will evaluate all of your scheduled tasks and determine if they need to run based on the server's current time.

So, when using Laravel's scheduler, we only need to add a single cron configuration entry to our server that runs the schedule:run command every minute. If you do not know how to add cron entries to your server, consider using a service such as Laravel Forge which can manage the cron entries for you:

* * * * * cd /path-to-your-project && php artisan schedule:run >> /dev/null 2>&1

Running The Scheduler Locally

Typically, you would not add a scheduler cron entry to your local development machine. Instead, you may use the schedule:work Artisan command. This command will run in the foreground and invoke the scheduler every minute until you terminate the command:

php artisan schedule:work

Task Output

The Laravel scheduler provides several convenient methods for working with the output generated by scheduled tasks. First, using the sendOutputTo method, you may send the output to a file for later inspection:

$schedule->command('emails:send')
         ->daily()
         ->sendOutputTo($filePath);

If you would like to append the output to a given file, you may use the appendOutputTo method:

$schedule->command('emails:send')
         ->daily()
         ->appendOutputTo($filePath);

Using the emailOutputTo method, you may email the output to an email address of your choice. Before emailing the output of a task, you should configure Laravel's email services:

$schedule->command('report:generate')
         ->daily()
         ->sendOutputTo($filePath)
         ->emailOutputTo('taylor@example.com');

If you only want to email the output if the scheduled Artisan or system command terminates with a non-zero exit code, use the emailOutputOnFailure method:

$schedule->command('report:generate')
         ->daily()
         ->emailOutputOnFailure('taylor@example.com');

Note: note The emailOutputTo, emailOutputOnFailure, sendOutputTo, and appendOutputTo methods are exclusive to the command and exec methods.

Task Hooks

Using the before and after methods, you may specify code to be executed before and after the scheduled task is executed:

$schedule->command('emails:send')
         ->daily()
         ->before(function () {
             // The task is about to execute...
         })
         ->after(function () {
             // The task has executed...
         });

The onSuccess and onFailure methods allow you to specify code to be executed if the scheduled task succeeds or fails. A failure indicates that the scheduled Artisan or system command terminated with a non-zero exit code:

$schedule->command('emails:send')
         ->daily()
         ->onSuccess(function () {
             // The task succeeded...
         })
         ->onFailure(function () {
             // The task failed...
         });

If output is available from your command, you may access it in your after, onSuccess or onFailure hooks by type-hinting an Illuminate\Support\Stringable instance as the $output argument of your hook's closure definition:

use Illuminate\Support\Stringable;

$schedule->command('emails:send')
         ->daily()
         ->onSuccess(function (Stringable $output) {
             // The task succeeded...
         })
         ->onFailure(function (Stringable $output) {
             // The task failed...
         });

Pinging URLs

Using the pingBefore and thenPing methods, the scheduler can automatically ping a given URL before or after a task is executed. This method is useful for notifying an external service, such as Envoyer, that your scheduled task is beginning or has finished execution:

$schedule->command('emails:send')
         ->daily()
         ->pingBefore($url)
         ->thenPing($url);

The pingBeforeIf and thenPingIf methods may be used to ping a given URL only if a given condition is true:

$schedule->command('emails:send')
         ->daily()
         ->pingBeforeIf($condition, $url)
         ->thenPingIf($condition, $url);

The pingOnSuccess and pingOnFailure methods may be used to ping a given URL only if the task succeeds or fails. A failure indicates that the scheduled Artisan or system command terminated with a non-zero exit code:

$schedule->command('emails:send')
         ->daily()
         ->pingOnSuccess($successUrl)
         ->pingOnFailure($failureUrl);

All of the ping methods require the Guzzle HTTP library. Guzzle is typically installed in all new Laravel projects by default, but, you may manually install Guzzle into your project using the Composer package manager if it has been accidentally removed:

composer require guzzlehttp/guzzle

Events

If needed, you may listen to events dispatched by the scheduler. Typically, event listener mappings will be defined within your application's App\Providers\EventServiceProvider class:

/**
 * The event listener mappings for the application.
 *
 * @var array
 */
protected $listen = [
    'Illuminate\Console\Events\ScheduledTaskStarting' => [
        'App\Listeners\LogScheduledTaskStarting',
    ],

    'Illuminate\Console\Events\ScheduledTaskFinished' => [
        'App\Listeners\LogScheduledTaskFinished',
    ],

    'Illuminate\Console\Events\ScheduledBackgroundTaskFinished' => [
        'App\Listeners\LogScheduledBackgroundTaskFinished',
    ],

    'Illuminate\Console\Events\ScheduledTaskSkipped' => [
        'App\Listeners\LogScheduledTaskSkipped',
    ],

    'Illuminate\Console\Events\ScheduledTaskFailed' => [
        'App\Listeners\LogScheduledTaskFailed',
    ],
];