CODEWITHSUNDEEP
laravelcachingredislaravel-8
Jesse Vlietveld
Jesse Vlietveld

Reputation: 393

Laravel Atomic Lock doesnt lock correctly

because my database is slow and I get a lot of API requests on the same time. I want to prevent the method from being executed twice at exactly the same time. I'm trying to implement the Laravel Atomic Lock as a solution (as described in: https://laravel.com/docs/8.x/cache#atomic-locks ) by the following way:

$lock = Cache::lock("service-{$id}", 10);

try
{
    $lock->block(5);
    // Lock acquired after waiting a maximum of 5 seconds...
} catch (LockTimeoutException $e)
{
    // Unable to acquire lock...
    return null;
}
//Execute code when lock is achieved
optional($lock)->release();
//Release lock when complete.

But for some reason I am still getting duplicate executions of the code despite the lock. I am using Redis as Cache driver. Anything I am doing wrong?

Upvotes: 2

Views: 1083

Answers (1)

halil
halil

Reputation: 21

Requests arriving at redis at the same time (milliseconds) can still pass this lock.

You can solve the problem by waiting for incoming requests for random a few milliseconds.

here is an example:

 $key=Auth::id(); //user unique id or something like     
 usleep(rand(0, 1000000));

 $time=explode(".", microtime(true));
 $time=$time[0].$time[1];

 if($time-Redis::get('lock_'.$key)<1000){
      return response()->json(['message'=>'Rate Limit Exceeded','errors' => ['Please wait a few second and try again!']], 429); 
      Redis::set('lock_'.$key,$time);
 }
 Redis::set('lock_'.$key,$time);

Upvotes: 0

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