Laravel Console Mutex

Prevents overlapping for Laravel console commands.

Laravel	Console Mutex
5.1.*	5.1.*
5.2.*	5.2.*
5.3.*	5.3.*
5.4.*	5.4.*
5.5.*	5.5.*
5.6.*	5.6.*

Table of contents

• Usage
• Strategies
• Advanced
  • Set custom timeout
  • Handle several commands
  • Custom mutex file storage
• Troubleshooting
  • Trait included, but nothing happens?
  • Several traits conflict?

Usage

1. Install package through composer:

   composer require illuminated/console-mutex

2. Use Illuminated\Console\WithoutOverlapping trait:

   use Illuminated\Console\WithoutOverlapping;
   
   class ExampleCommand extends Command
   {
       use WithoutOverlapping;
   
       // ...
   }

Strategies

Overlapping can be prevented by various strategies:

• file (default)
• mysql
• redis
• memcached

Default file strategy is fine for a small applications, which are deployed on a single server. If your application is more complex and, for example, is deployed on a several nodes, then you probably would like to use some other mutex strategy.

You can change mutex strategy by specifying $mutexStrategy field:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    protected $mutexStrategy = 'mysql';

    // ...
}

Or by using setMutexStrategy method:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    public function __construct()
    {
        parent::__construct();

        $this->setMutexStrategy('mysql');
    }

    // ...
}

Advanced

Set custom timeout

By default mutex is checking for a running command, and if it finds such, it just exits. However, you can manually set timeout for a mutex, so it can wait for another command to finish it's execution, instead of just quitting immediately.

You can change mutex timeout by specifying $mutexTimeout field:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    protected $mutexTimeout = 3000; // milliseconds

    // ...
}

Or by using setMutexTimeout method:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    public function __construct()
    {
        parent::__construct();

        $this->setMutexTimeout(3000); // milliseconds
    }

    // ...
}

There are three possible options for $mutexTimeout field:

• 0 - check without waiting (default);
• {milliseconds} - check, and wait for a maximum of milliseconds specified;
• null - wait, till running command finish it's execution;

Handle several commands

Sometimes it is useful to set common mutex for a several commands. You can easily achieve this by setting them the same mutex name. By default, mutex name is generated based on a command's name and arguments. To change this, just override getMutexName method in your command:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    public function getMutexName()
    {
        return "icmutex-for-command1-and-command2";
    }

    // ...
}

Custom mutex file storage

If you're using file strategy, mutex files will be stored at storage/app folder, by default. However, you can change storage folder by overriding getMutexFileStorage method in your command:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    public function getMutexFileStorage()
    {
        return storage_path('my/custom/path');
    }

    // ...
}

Troubleshooting

Trait included, but nothing happens?

Note, that WithoutOverlapping trait is overriding initialize method:

trait WithoutOverlapping
{
    protected function initialize(InputInterface $input, OutputInterface $output)
    {
        $this->initializeMutex();
    }

    // ...
}

If your command is overriding initialize method too, then you should call initializeMutex method by yourself:

class ExampleCommand extends Command
{
    use WithoutOverlapping;

    protected function initialize(InputInterface $input, OutputInterface $output)
    {
        $this->initializeMutex();

        $this->foo = $this->argument('foo');
        $this->bar = $this->argument('bar');
        $this->baz = $this->argument('baz');
    }

    // ...
}

Several traits conflict?

If you're using some other cool illuminated/console-% packages, well, then you can find yourself getting "traits conflict". For example, if you're trying to build loggable command, which is protected against overlapping:

class ExampleCommand extends Command
{
    use Loggable;
    use WithoutOverlapping;

    // ...
}

You'll get fatal error, the "traits conflict", because both of these traits are overriding initialize method:

If two traits insert a method with the same name, a fatal error is produced, if the conflict is not explicitly resolved.

But don't worry, solution is very simple. Override initialize method by yourself, and initialize traits in required order:

class ExampleCommand extends Command
{
    use Loggable;
    use WithoutOverlapping;

    protected function initialize(InputInterface $input, OutputInterface $output)
    {
        $this->initializeMutex();
        $this->initializeLogging();
    }

    // ...
}