How can i run async only once?

[pyaehein]

I used async queue. And, I want to run my background function only once. How can i do that ?
Here is my code. Is it right or wrong ? What should i fix ? And how can i know which job failed ?

$job = new myjob($var1, $var2);
$this->dispatch($job);
$job->release();
if ($job->attempts() >= 1)
{
$job->delete();
//will do other process when job fail
}