readme.md

Multi Server Event

This package extends Laravel's native Event class to include the ability to block events from occurring aross multiple servers, as would be the case if you have a laravel instance behind a load balancer in an auto-scaling situation.

It uses a database table to track the currently running process, and each server generates a unique key to lock the command. In order to prevent a condition where a short-running command's lock doesn't last long enough, we are implementing a minimum 10 second break between the completion of the command and its next execution time, so if a command runs every minute but takes between 50 and 59 seconds to complete, the next command will be delayed one more minute.

Installation

$ composer require jdavidbakr/multi-server-event

The new event structure uses a database table to track which server is currently executing an event. You must create the database table using the provided migration. To do this, add the following to the $commands array in \App\Console\Kernel.php:

\jdavidbakr\MultiServerEvent\Commands\MultiServerMigrationService::class,

then perform the migration

php artisan make:migration:multi-server-event
php artisan migrate

Now we want to change the default schedule IoC to use this alternate one. In app\Console\Kernel.php add the following function:

/**
 * Define the application's command schedule.
 *
 * @return void
 */
protected function defineConsoleSchedule()
{
    $this->app->instance(
        'Illuminate\Console\Scheduling\Schedule', $schedule = new \jdavidbakr\MultiServerEvent\Scheduling\Schedule
    );

    $this->schedule($schedule);
}

Usage

When composing your schedule, simply add "withoutOverlappingMultiServer()" to the command, i.e.

$schedule->command('inspire')
    ->daily()
    ->withoutOverlappingMultiServer();

This will prevent multiple servers from executing the same event at the same time.