Locking console batch process in Yii2 - concurrency

Question

I'm developing a web application based on the Yii2 framework.
Every 12 hours the application needs to run a batch process to update some DB tables and it takes 5-10 seconds. In order to do that, I created a console command (say ./yii dummy/index) that is called by the windows task scheduler using a .bat script. However, while running the task, the application Web GUI is still running. Does Yii2 autonomously stops any web interaction while executing the task or should I lock manually the system to avoid any inconsistency issues? If is that so, how can I stop web interaction while executing the console process and restart them when it's completed?

Answer 1

Console and web apps are completely autonomous. Running a console command will in no way prevent the web app from running.
The easiest way to solve this problem would be to set some kind of mutex in your console command and check for it in your web application. For that, Yii2 offers a variety of mutex classes all derived from yii\mutex\Mutex.
You add a mutex to your console and web app configs:
'mutex' => [
'class' => 'yii\mutex\MysqlMutex',
],
In your console command you need to acquire the mutex (allow it to wait for a few seconds):
$mutexResult = Yii::$app->mutex->acquire('example-mutex', 10);
if ($mutexResult) {
echo 'Could not acquire lock'.PHP_EOL;
Yii::$app->end();
}
And when you're done, release it:
Yii::$app->mutex->release('example-mutex');
In your web application you then check if the mutex is available. I believe current application template will generate controllers that extend the yii\web\Controller class. You should create your own base controller class that extends yii\web\Controller and define its beforeAction method:
class BaseController extends \yii\web\Controller
{
public function beforeAction($action)
{
$mutexResult = Yii::$app->mutex->acquire('example-mutex', 20);
if ($mutexResult) {
Yii::$app->mutex->release('example-mutex');
} else {
echo 'Console app is running';
return false;
}
return parent::beforeAction($action);
}
}
Then extend all your web application's controllers from this BaseController class.
This way Yii will check for this flag before any action is executed.